text:
If I have Ashaya out and return Quirion Ranger with itself, can it target itself?
If I have Lotus Cobra, Ashaya, Soul of the Wild, Nadu, Winged Wisdom, and Quirion Ranger out, can I target Quirion Ranger with its own ability while returning Qurion Ranger to my hand?

Yes, the combo works. Quirion Ranger sees itself being targeted and thus triggers the ability granted by Nadu.
A creature can target itself with its own ability, even if payment for that ability causes that creature to change zones. See for example here.
The other question would be, does the ability granted by Nadu trigger? The answer is also "yes". Since Quirion Ranger's activated ability requires a target, it only goes on the stack if all its chosen targets are legal during the ability activation process, which is identical to the spellcasting process for the relevant parts.

601.2c The player announces their choice of an appropriate object or player for each target the spell requires. [..]

If Quirion Ranger was not a legal choice of targets, the game state would return to just before the ability activation was announced:

601.2e The game checks to see if the proposed spell can legally be cast. If the proposed spell is illegal, the game returns to the moment before the casting of that spell was proposed (see rule 730, “Handling Illegal Actions”).

If it is a legal choice, however, that means Quirion Ranger has been successfully targeted, and Nardu's ability triggers now.

603.2. Whenever a game event or game state matches a triggered ability’s trigger event, that ability automatically triggers. The ability doesn’t do anything at this point.

It will wait to enter the stack until after the currently activating ability has gone on the stack.

603.3. Once an ability has triggered, its controller puts it on the stack as an object that’s not a card the next time a player would receive priority.

The process continues to paying the ability's cost; only now does the Quirion Ranger return to hand and the activated ability goes on the stack:

601.2f The player determines the total cost of the spell.

601.2h The player pays the total cost.  [..]

601.2i Once the steps described in 601.2a–h are completed, effects that modify the characteristics of the spell as it’s cast are applied, then the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell’s controller had priority before casting it, they get priority.

Now Nadu's ability goes on the stack. When it resolves, it does not matter that the Quirion Ranger is no longer on the battlefield. Nadu's ability is not targeted. It exists independently of and does not require any information about its source.
You may then recast Quirion Ranger, get your Lotus Cobra trigger, and repeat the combo indefinitely.

Yes, that works fine. When activating abilities, you choose targets before paying costs, so Quirion Ranger is still on the battlefield while you are choosing targets, which means that it is a valid target.
However, it's not entirely clear whether doing that will trigger the ability granted by Nadu. I can't find any rule or ruling that establishes when exactly a triggered ability with a condition like "Whenever (something) becomes the target of a spell or ability..." triggers. The problem is that if an ability like that triggers only after costs are paid, then I think it wouldn't trigger in this situation, because the ability wouldn't exist at that time.

As judge, I would rule that it would trigger. This is similar to how death triggers still work when there is a board wipe, even though the creature with the triggered abilility is already in the graveyard when the trigger. As long as the condition is met at some point, the trigger will be put on stack the next time a player would get priority.

Death triggers are explicitly in the category of triggers that look back in time to before the triggering event to determine whether any abilities need to trigger. See rule 603.10 for more information. However, the ability granted by Nadu is not in that category, so the same logic doesn't apply.


text:
Dictate of Erebos and Bestowed creatures
Bestow is a mechanic with the following reminder text:

(If you cast this card for its bestow cost, it’s an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)

Dictate of Erebos has the following effect:

Whenever a creature you control dies, each opponent sacrifices a creature.

Consider the following case:

My opponent controls a Dictate of Erebos

I control a Creature which has, as an Aura attached to it, a card with Bestow (in my case, an Underworld Coinsmith with Hopeful Eidolon as an Aura)

I control a single other creature, which I want to avoid sacrificing (in my case, a Doomwake Giant)

A single effect kills two of my opponent’s creatures (in my case, the Doomwake Giant’s Constellation effect triggered while he had two 1/1s)

I choose, as my first sacrifice, the Creature enchanted with the Bestowed card (in my case, the Underworld Coinsmith above)

In this situation, does the Bestowed card (e.g. the Hopeful Eidolon above) revert to being a Creature in time for me to choose it as the next sacrifice?
Or does it only revert to being a Creature after all triggered instances of Dictate of Erebos have resolved, forcing me to sacrifice the creature I want to save (e.g. the Doomwake Giant above)?

You can use [mtg:Card Name] to tag cards. I don't recommend it for cards with an apostrophe in the name.

For cards with an apostrophe in the name, you can tag it by just leaving out the apostrophe (and leave out the s after the apostrophe if there is one).

@GendoIkari what about weird cases where the apostrophe is just part of the name, not a possessive, and more significant parts come after it?

@KRyan I don't know if there's a solution to that, currently.

Well, there's not a lazy solution. You can always search for the card on the Gatherer and link it yourself.

You may sacrifice Underworld Coinsmith, and then you may sacrifice Hopeful Eidolon.
Whenever a creature dies, all of its enchantment(s) become unattached. Normally, they would be sent straight to the graveyard as a state based action. However, enchantments with Bestow immediately become a creature instead due to rule CR 702.102a. The commonly used slang terminology for this action is "falls off".
Triggers from Dictate of Erebos resolve one at a time. If you sacrifice Underworld Coinsmith to the first trigger, then Hopeful Eidolon immediately "falls off" and is ready to be sacrificed to the second trigger.

702.102a If you chose to pay this spell’s bestow cost, it becomes an Aura enchantment and gains enchant creature. These effects last until the permanent this spell becomes becomes unattached.

I just want to point out that that Comprehensive Rules link is actually out of date. It doesn't have the rules for Khans of Tarkir. I would suggest instead linking to MTG Salvation, which is completely up to date. Specifically, I'd suggest linking to this page.

The rules you linked also don't have the Magic 2015 rules changes.

Alternatively, this page links to the most up to date official rule book.

Minor improvement: Triggers from Dictate of Erebos resolve one at a time => Abilities on the stack (including the triggered ability from Dictate of Erebos) resolve one at a time

@murgtroid99 Thanks. I fixed the link, and I double checked that the rule number was still the same. I hadn't seen the new page until you pointed it out.

@Rainbolt That's not surprising. I have not yet found a Google search that results in a link to that page. Luckily, there hasn't been a major change in rule numbers since M14.

Dictate of Erebos' effect goes onto the stack for each instance it was triggered. The Hopeful Eidolon becomes a creature as soon as the creature it's attached to is removed from the battlefield so it will be a creature before the second Erebos trigger resolves, so you may sacrifice it.

Thanks for the answer; I've accepted the other one because rules quotes, but I did upvote both. Also, is your nick a reference to Illusion of Gaia? Cuz that's awesome.

Yeah, I wrote this from memory and went to add the reference after the fact, but Rainbolt beat me to it.

@KRyan I just saw the edit to your comment, and yes it is a reference to Illusion of Gaia. You win some sort of award for being the 3rd person to notice it (or notice it and then say something) in the 10+ years I've used the moniker as my online alias.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
Mimic Vat and Exiling
If I used Mimic Vat on a Licid, created a copy of that Licid, and attached it to a creature, would I still have to exile it during my end step even though it's now an enchantment?

Yes.  The relevant part of Mimic Vat's text reads:

Put a token onto the battlefield that's a copy of the exiled card. It gains haste. Exile it at the beginning of the next end step.

The text clearly tells you to exile the token that the Vat created regardless of whether it's a creature or not.  If a Licid token becomes an enchantment, it is still the same object and thus still the same token, and so the Vat's delayed triggered ability will still find it and exile it at the next end step.

It may be worth emphasizing that the reason this is clear (i.e. the reason it's clear you exile the token whether it's a creature or not) is simply that the text does not say anything about it being or not being a creature. It's an often-quoted rule of thumb that Magic cards should be taken literally except when the rules specify otherwise; this is a prime example.

@DavidZ, That's not really true. Take for example "Create an enchantment token (with some characteristics) and a creature token (with some characteristics). Exile the creature token at the beginning of the next end step." From what you say, it sounds like it will only exile a creature token, except it will still exile it even if it's no longer a creature.

@ikegami As I said, it's a rule of thumb; there are rare exceptions, such as the one you brought up. That being said, are you sure it would actually be templated that way?

@DavidZ, You actually said it was a prime example, but I showed otherwise. Yes, there are things templated that way. e.g. Diabolic Servitude.

@ikegami (1) no, you didn't. jwodder's answer is a prime example of the literal interpretation being the correct one, and nothing you said refutes that. If you'd like to discuss this further it's probably time to move it to chat. (2) Thanks; I couldn't think of an example offhand so I wasn't sure.

I've proven it's wrong to interpret it literally, so it can't possibly be a prime example of the literal interpretation being the correct one

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Are there cards which turn life gain into damage instead?
I was playing Hearthstone the other day and was intrigued by a card that causes healing spells to do damage instead.  I was curious if there was ever anything printed in MTG that would have a similar effect, i.e. every time you would gain X life you take X damage instead.

As an interesting aside: The lack of a distinction between damage and loss of life in Hearthstone causes Auchenai Soulpriest (the card you are talking about) to interact VERY poorly with mistress of pain (mistress of pain will kill you the moment it damages anything)

You should clarify: do you mean [an effect that causes life gain for you to causes life loss for your opponent] or [an effect that would normally cause life gain for an opponent causes life loss instead]

I know this question is pretty old, but in HS creatures have their own life points (instead of just a constitution score) and thus can be healed (instead of just preventing damage the moment it happens) - As a result, Auchenai Soulpriest works whenever anyone heals anything (it takes damage instead). Some of the answers are geared towards "you gain life the opponent deals damage", and this is not what this question is asking, is it?

Yes, there's Rain of Gore.

If a spell or ability would cause its controller to gain life, that player loses that much life instead

As well as False Cure.

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life he or she gained.

There's also Sanguine Bond.

Whenever you gain life, target opponent loses that much life.

Also Transcendence.

And Rain of Gore.

@HaoYe, good one, I forgot about that. Edited. I was unsure about Transcendence, since it doesn't literally make you lose life when you use a life gain effect (although the end result is very similar).

Tainted Remedy: if an opponent would gain life, that player loses that much life instead

@JoeW This does answer the question. By providing one example, the author has demonstrated that this type of card does exist in MTG.

@Rainbolt, I see the mistake I made now, is there anyway to undo the review action?

@JoeW Currently, no, but you can show your support for such a feature by upvoting this proposal. Until then, you just have to rely on our moderators to make the right call.

There is Vizkopa Guildmage, which has the following activated ability:

{1}{W}{B}: Whenever you gain life this turn, each opponent loses that much life.

I play a health to damage deck. All I have to do is pay 1 white, 1 black, and 1 mana of any color each turn, and play any health gaining card, and my opponent loses that much health.
I run 4 of these with some instances of Font of Vigor, Centaur Healer, Kheru Bloodsucker (gain health when creature of toughness 4 or higher is killed) and finish with a Soul of Innistrad: for {3}{B}{B}, bring 3 creatures from grave to my hand. These make an infinite loop!

I've done some copyediting to this answer and added some formatting. Just FYI, you can convert those mana symbols to the actual icons using an unofficial plugin of ours I wrote.

Look at False Cure and cards from the masques block. you can win without anything but a False Cure and several cards with the alternate casting cost of having your opponents gain life. Reverent Silence, Refreshing Rain, Skyshroud Cutter and Invigorate all have the alternate casting cost. you need a forest or overgrown tomb/bayou in play then cast false cure and win by having them gain/lose life. fun mechanic very meme-ish. not competative but if you pull it off it your friends will think it is.

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Athreos, God of Passage, and Martyr of Sands
My opponent has Athreos, God of Passage on the field.  They then play Martyr of Sands and use her ability "{1}, Reveal X white cards from your hand, Sacrifice Martyr of Sands: You gain three times X life."  They sacrifice the Martyr, triggering Athreos's ability.  I choose not to pay 3 life, and they return the Martyr to their hand.
Does my opponent still gain life even though Martyr of Sands isn't in the graveyard as her ability resolves?

Since nothing but the sacrifice tries to move the Martyr, the Martyr would still be on the battlefield if it wasn't sacrificed. The Martyr was sacrificed, so the cost was payed, so your opponent gains the life[1]. Athreos caused a triggered ability to happen to Martyr after Martyr's ability was put on the stack, but that doesn't matter.
The steps taken in order are:

The costs are paid for Martyr of Sands's ability: One mana is paid, you reveal some number of white cards from your hand, and Martyr of Sands is placed in the graveyard.
Martyr of Sands's ability is placed on the stack, but doesn't resolve yet.
Athreos's triggered ability is triggered and then placed on the stack.
Athreos's ability resolves. In this case, you decide not to pay three life, and Martyr of Sands is returned to your opponent's hand.
Martyr of Sands's ability resolves, causing your opponent to gain three times X life.

Additionally, your opponent would still gain the life even if the sacrifice itself was replaced with another action[CR 117.11][2]: the cost to activate the ability would have changed, but the ability would still have the same effect when resolving.

117.11. The actions performed when paying a cost may be modified by effects. Even if they are, meaning the actions that are performed don’t match the actions that are called for, the cost has still been paid.

The sacrifice happened (even if the creature didn't end up in the graveyard), so abilities that trigger when you sacrifice a creature (such as Dragon Appeasement's second ability) will trigger.
The sacrifice itself was replaced, so abilities that trigger when you sacrifice a creature (such as Dragon Appeasement's second ability) won't trigger[CR 614.6].

Do you want to expand on this using rule 117.11? (addresses a different question, but could be informative for OP)

@Hao Ye, Good idea, done.

Are you saying if for instance i cast magma spray in response to martyr's ability the sacrifice would then be replaced and no life gain would happen?

@JustinFincher Sacrificing the Martyr is part of the cost of activating the ability (activated abilities are of the form "cost: effect"). You pay the cost before it goes on the stack and players get priority, so if you activate the ability, once anyone gets a chance to cast a spell, it's already sacrificed.

then i don't understand what ikegami means in his second point." The sacrifice itself was replaced, so abilities that trigger when you sacrifice a creature (such as Dragon Appeasement's second ability) won't trigger[CR 614.6]"

what would be an instance of that?

@Justin Fincher, There isn't (and there likely never will be) anything that replaces sacrifice specifically, but it's possible for costs to be replaced. 117.11 actually has an example in the rules. Example: A player controls Psychic Vortex, an enchantment with a cumulative upkeep cost of “Draw a card,” and Obstinate Familiar, a creature that says “If you would draw a card, you may skip that draw instead.” The player may decide to pay Psychic Vortex’s cumulative upkeep cost and then draw no cards instead of drawing the appropriate amount. The cumulative upkeep cost has still been paid.

@ikegami Sure. I do think your point (3) is a little iffy, though. Replacing costs is not hypothetical, but replacing sacrifices is, and that's what makes citing 117.11 confusing in the context of your answer.

@Aetherfox, ug, sometimes I think the effect of triggered abilities are replacement effects of static abilities. Thanks for the fix. (Nit: Abilities are placed on the stack, not effects.)

Your opponent does still gain the life. Nothing in the ability says that the Martyr has to be in their graveyard to gain the life. The sacrifice cost was paid, and once the ability was on the stack, it existed independent of the creature card (CR 112.7a).

They will still gain life. This is because sacrificing the Martyr is sacrificed and once that happens the ability doesn't care what happens to her.
What happens is your opponent activates the Martyr's ability, sacrificing her, paying the mana, and revealing white cards from your hand. Once they've done all of that the ability goes on the stack. After it is on the stack Aethreos's ability triggers and when it resolves you allow the Martyr to return to their hand. At this point the Martyr's ability is still on the stack waiting to resolve, and since there is nothing in the effect that requires the Martyr to be in the graveyard when it resolves it is perfectly happy to give your opponent life.


text:
Can Enchantment Creature play its enchanted ability?

When I play Nylea's Emissary and decide to not pay its Bestow cost, does that mean that it is a 6/6 Enchantment Creature with Trample? Does the enchanted creature spell only work if I pay the Bestow cost to enchant another creature?

Close, but not quite. Bestow is an alternative way of casting the card, once you choose to cast it not for its Bestow cost it is a regular 3/3 Enchantment Creature with Trample (It isn't enchanting itself so it doesn't get +3/+3 from its ability). There is no way to attach it to a creature once you have cast it as a Creature.

702.102. Bestow
702.102a Bestow represents two static abilities, one that functions while the card with bestow is on the stack and another that functions both while it’s on the stack and while it’s on the battlefield. “Bestow [cost]” means “You may cast this card by paying [cost] rather than its mana cost.” and “If you chose to pay this spell’s bestow cost, it becomes an Aura enchantment and gains enchant creature. These effects last until one of two things happens: this spell has an illegal target as it resolves or the permanent this spell becomes, becomes unattached.” Paying a card’s bestow cost follows the rules for paying alternative costs in rules 601.2b and 601.2e–g.
702.102b If a spell’s controller chooses to pay its bestow cost, that player chooses a legal target for that Aura spell as defined by its enchant creature ability and rule 601.2c. See also rule 303.4.
702.102c A spell’s controller can’t choose to pay its bestow cost unless that player can choose a legal target for that spell after it becomes an Aura spell.
702.102d As an Aura spell with bestow begins resolving, if its target is illegal, the effect making it an Aura spell ends. It continues resolving as a creature spell and will be put onto the battlefield under the control of the spell’s controller. This is an exception to rule 608.3a.
702.102e If an Aura with bestow is attached to an illegal object or player, it becomes unattached. This is an exception to rule 704.5n.

If the comprehensive rules are a little confusing to beginning players reading this, there's also very readable section in The Mechanics of Theros describing bestow.


text:
"Put into graveyard" versus "exile graveyard"
Does the ability "Exile all cards from target player's graveyard" counter "When ~ is put into a graveyard from anywhere, its owner shuffles his or her graveyard into his or her library"?
For example: if Emrakul, the Aeons Torn is put into the graveyard, will activating Tormod's Crypt counter its effect?

Kind of.
When Emrakul hits the graveyard, his ability

When Emrakul is put into a graveyard from anywhere, its owner shuffles
  his or her graveyard into his or her library.

goes onto the stack. Then priority will first go to the active player and then to the other. After receiving priority, Tormod's Crypt can be activated.

Exile all cards from target player's graveyard.

All cards go into the exile zone.
After that, Emrakul's trigger resolves, and its controller will shuffle his or her empty graveyard into his or her library.

Effectively, the ability is countered. In actuality, using precise MtG verbage, the ability still happens, but the graveyard has zero cards in it.

So Emrakul is exiled too ? or it return to the library ?

yeah, everything is exiled.

Emrakul has to enter the graveyard, from anywhere, for his ability to work. If he is in the graveyard when Tormod's Crypt resolves on top of his ability in the stack, he is exiled.

Note that Emrakuls ability is a triggered ability. So it goes onto the stack and can be responded to. If you take a card like Progenitus , it's different. The if-clause indicates a replacement effect, which will not go onto the stack. There is no possibility to prevent Progenitus from being reshuffled into the librabry

In contrast, an ability like Anafenza's ("If a creature card would be put into an opponent's graveyard from anywhere, exile it instead.") would cause Emrakul to never enter the graveyard in the first place, so Emrakul's ability wouldn't trigger at all.

Just remember that shuffling a graveyard into a library still causes the library to be shuffled even if the graveyard is empty.


text:
"At the beginning of the end step" versus "Until end of turn"
If Deceiver of Form is used to copy my Biovisionary, does his "at the beginning of the end step" ability resolve before Deceiver of Form's "until end of turn" ability expires, thus making Deceiver of Form a fairly easy way to "win the game"?

I don't know if getting Deceiver forms with 4+ other creatures out and Biovisionary on the top would be called fairly easy.

i can typically play deceiver on turn 4 and i already have 3+ scions plus the creatures that spawned them

it's not super easy but it's easier than playing 4 of them or playing one and 3 clones.

So you rely just on the ability to cycle through your entire deck in order to get a Biovisonary on the top?

i have a few sylvan tutors and other ways to get it on top the point of the question was just to see if beggin and end would resolve separately

given that it's blue and green it stands to reason the majority of my deck would then be control and deck thinning mana search cards. so it's plausible at least, just a fun concept i thought of when i pulled a deceiver

Mirrorweave is also an easy way to do it. Be careful though that when your opponent also has 4 creatures he will win if you cast Mirrorweave on your turn

Yes.  "At the beginning of the end step" abilities trigger at, well, the beginning of the end step, while "until end of turn effects" expire at the beginning of the cleanup step, which is after the end step.  Thus, Biovisionary's ability will trigger and resolve while all your creatures are still Biovisionaries.
Comprehensive Rules references:

512.1. The ending phase consists of two steps: end and cleanup. [This appears to be the closest thing to an explicit statement that end precedes cleanup.]
514.2. Second, the following actions happen simultaneously [during the cleanup step]: all damage marked on permanents (including phased-out permanents) is removed and all “until end of turn” and “this turn” effects end. This turn-based action doesn’t use the stack.


text:
Will Karlov get multiple +1/+1 counters with Soul Warden when multiple tokens are created simultaneously?
When I have Karlov of the Ghost Council and Soul Warden on the battlefield and I cast something like Lingering Souls, does Karlov get two +1/+1 counters twice since two spirits enter the battlefield or only once since I cast Lingering Souls once?
The same thing applies to beautiful cards such as Conqueror's Pledge - does Karlov get two +1/+1 counters six times or only once?

By the way: there are no +2/+2 counters involved in this situation. Only +1/+1 counters. (+2/+2 counters are only used on a few very old cards.)

Soul Warden's ability reads:

Whenever another creature enters the battlefield, you gain 1 life.

When Lingering Souls resolves, there are two separate instances of "another creature" entering the battlefield, and so the ability triggers twice, and you gain 1 life twice in two separate events.  Thus, Karlov's ability will trigger twice, and he will gain four +1/+1 counters.  Likewise, using Conqueror's Pledge instead will net you 6 life and twelve counters.
Compare rule 603.2c and its example:

603.2c An ability triggers only once each time its trigger event occurs. However, it can trigger repeatedly if one event contains multiple occurrences. See also rule 509.4.
Example: A permanent has an ability whose trigger condition reads, “Whenever a land is put into a graveyard from the battlefield, . . . .” If someone casts a spell that destroys all lands, the ability will trigger once for each land put into the graveyard during the spell’s resolution.


text:
Creatures with "Whenever you cast a colorless spell, untap ~"
Are there any other creatures that have an ability that's the same as Nettle Drone's second ability, "Whenever you cast a colorless spell, untap [card name]"?
I'm not sure how exactly to search for it. Any insight?
The things I tried on Gatherer brought back a lot of false positives.

I'm not sure what you tried on gatherer, but if you actually wanted to search for that, just leave out the card name and use double quotes to get an exact match: ["whenever you cast a colorless spell, untap"]. (The brackets aren't part of the query.) But as the more-helpful answers have pointed out, that's too specific a query: it only finds Nettle Drone.

If you look for, "whenever you cast an instant or sorcery" in gatherer, you'll see a large number of very interesting effects.  Gelectrode in particular is a personal favorite.  Not exactly what you're looking for...

One option is to use Scryfall, which uses "~" in card text search to mean the name of the card that the text is on. So, for example, you can search

o:"Whenever you cast a colorless spell, untap ~"

This gives exactly one result: Nettle Drone.
In addition, Scryfall has a regular expression search that supports the same meaning of "~". So if you do the following card text search, you end up at Nettle Drone:

re:"Whenever you cast a colorless spell, untap ~"

For a slightly broader set of results, you can search for

re:"Whenever * (cast|casts) (a|an)* spell,* untap ~"

This finds every ability of the form "Whenever [a player] cast(s) a(n) [characteristic] spell, untap [this permanent]". It finds a total of 9 cards, two of which untap when you cast any colorless spell: Dwarven Patrol and Nettle Drone.
You can also use this less-accurate regex:

re:"Whenever * (cast|casts) (a|an)* spell,* untap"

This captures more cards outside our intentions but with a similar effect (e.g. Paradox Engine, Jeskai Ascendancy). More importantly, it includes cards like Blistercoil Weird which say "untap it" (in reference to themselves) following some other effect that's also occurring.

Thanks, I never have used magiccards.info I've heard of it but not used it. While the results are somewhat dissapointing this did answer my question.

If you're looking for cards that untap based on some event, a query on magiccards.info like o:whenever o:untap o:cast might be what you're looking for. Essentially, you are trying to distill down the nature of what you are looking for.  You want a trigger (whenever), from an event (cast), and an action (untap).
So, the example query gives all cards that check the casting of a spell and untap something.  To make it more specific, adding another modifier (colorless) shows that Nettle Drone is the only card with the same trigger and same action.

That's way too specific. At the most, I'd look for cards with the following phrases:

Whenever
cast a colorless spell / casts a colorless spell
untap

That will allow "Whenever a player casts a colorless spell", for example. And it will allow compound effects that include untapping.
Even with those loosen criteria, there's only one match.


text:
If Ink-Eyes brings a creature back and then her owner loses in a multiplayer game, does the rezzed creature go to graveyard?
So say I have a creature in my graveyard in a 3-player game, and one of my opponents uses Ink-Eyes, Servant of Oni to bring it back from the dead. That player then goes on to lose. Does my creature come back under my control, or go back to my graveyard?

It will be exiled. The card would go back under your control if there was a temporary effect granting your opponent the control of your creature, e.g. Mind Control or Act of Treason. This is not the case, so the object under your opponent control would be exiled (since it is not the object he owns and it doesn't leave the game). The ruling in question has an example that covers it:

800.4a When a player leaves the game, all objects (see rule 109) owned by that player leave the game and any effects which give that player
control of any objects or players end. Then, if that player controlled
any objects on the stack not represented by cards, those objects cease
to exist. Then, if there are any objects still controlled by that
player, those objects are exiled. This is not a state-based action. It
happens as soon as the player leaves the game. If the player who left
the game had priority at the time he or she left, priority passes to
the next player in turn order who’s still in the game.
...
Example: Alex casts Bribery, which reads, “Search target opponent’s
library for a creature card and put that card onto the battlefield
under your control. Then that player shuffles his or her library,”
targeting Bianca. Alex puts Serra Angel onto the battlefield from
Bianca’s library. If Bianca leaves the game, Serra Angel also leaves
the game. If, instead, Alex leaves the game, Serra Angel is exiled.

The second player could bring it back with something like Ruin Processor, right? Since it's exiled and owned by OP?

Sure, nothing stops him from using it. Any other card that somehow works with exile will operate normally. E.g. you could cast Misthollow Griffin if it was exiled that way.


text:
Why do Treasure tokens need to be tapped?
I was just pondering the design of the Treasure token as a mechanic and wondering why its text is "Tap, Sacrifice this artifact: Add one mana of any color."
Couldn't it just be "Sacrifice this artifact: Add one mana of any color." instead? What constraint or value does the tap requirement add other than adding slightly more text to all the cards that have explainer text for what a Treasure token is?

This seems like it is essentially answered by https://boardgames.stackexchange.com/questions/48543/why-do-some-artifacts-require-tapping-and-sacrificing-as-an-activation-cost. In particular, check the comments on the answer to that question.

@murgatroid99 Agree it's answered in the comment, but comments are ethereal and we shouldn't rely on them existing in the future ;)

It's to prevent "double tapping" the token for two mana when used in conjunction with other abilities, most notably Improvise but also things like Urza, Lord High Artificer. Without the tap constraint on the Treasure, you can tap the treasure for one mana with Improvise and then sacrifice it for another mana.
Gold tokens do exist without the tap requirement, but R&D found them to be too powerful:

The Gold tokens were problematic with the improvise mechanic from Aether Revolt, so we had to add a tap and change the token’s name.

Same reasons why fetches need to be tapped. So you don't get two mana out of them with urborg tomb of yawgmoth.

Are there not also cards that could cause them to enter the game tapped which would prevent them from being used?

@JoeW There are, going at least as far back as 4th Edition and getting reprinted occasionally. But I don't believe that working around those interactions was considered problematic.

Right, things that cause it to enter the battlefield tapped and prevent it from untapping can be worked around but they can also prevent someone from using them if they don't account for that in the design.

@JoeW Yes, there are effects that can make all artifacts come into play tapped; the design team has also been recently making cards that deliberately create tapped treasure tokens as a way to lower their power level (and lessen the possibility of a degenerate combo). Some recent examples include Gala Greeters, Blood Money, and Ognis, the Dragon's Lash.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Cloudshifting Angel of Serenity in the middle of combat
I have a very specific situation in mind.  My friend attacks me with some flying creatures, one of which is Angel of Serenity.  Before I declare blockers, I cast a Moonmist and an Atarka's Command on my werewolves to block them.  My friend then plays a Cloudshift on Angel of Serenity; does her ability happen at that moment while we're fighting?  That is, does he exile three of my werewolves and remove the angel from combat?

Why wouldn't the ability trigger then? What else do you expect might happen?

Your friend can play Cloudshift before or after you have declared blockers. Either way Cloudshift will resolve before the combat damage step. This means their Angel of Serenity is removed from combat, your friend may choose to exile up to three creatures, and any previously exiled cards are returned to their owner's hands.
If I'm correct this is the order in which everything happens, assuming your friend casts Cloudshift after you declared blockers:

Opponent casts Cloudshift targeting Angel of Serenity, this goes on the stack and it resolves (assuming no counter spells and no further combat tricks).
Angel of Serenity gets exiled (is removed from combat) and its leaves the battlefield ability triggers. Then the Angel of Serenity card returns to the battlefield, creating a new instance of the Angel, and its enters the battlefield ability triggers. Both triggers then go on the stack in either order.
As the enters the battlefield ability goes on the stack, opponent may choose up to three target creatures.
Angel of Serenity's enters the battlefield ability resolves and the chosen target creatures are exiled.
Angel of Serenity's leaves the battlefield ability resolves and any previously exiled creatures are returned to their owners hands. These are any creatures that were exiled when the original instance of Angel of Serenity entered the battlefield.

When the stack is empty and both players pass priority you move to the combat damage step.

Would "Both triggers then go on the stack in either order" really apply here, since the two actions are consecutive (leave, return) even though they are both part of the spell resolving?

Yes. They go on the stack at the same time.

@JonTheMon, Triggered abilities are only placed on the stack as a player would get priority, which is to say after Cloudshift has finished resolving, which is to say after the original Angel left and the new Angel entered. When a player must put more than one triggered ability on the stack at the same time, he gets to choose the order in which they are placed on the stack. The fact that one triggered before the other is irrelevant.

You're right as per 603.3b

The Angel's abilities trigger when it enters or leaves the battlefield.  Exile, even for just long enough of one instant's effect, counts as leaving the battlefield, and coming back into play counts as entering it.
Any cards previously exiled by the Angel would return to your hand, and a new set of three creatures can be chosen for exile.  It's all right there, and it all happens right then.


text:
Does Storm count opponents' spells?
The definition of storm (such as in Grapeshot) is:

Storm (When you play this spell, put a copy of it onto the stack for each other spell that was played before it this turn. If the spell has any targets, you may choose new targets for any number of the copies.)

Does Storm count the spells played by the opponent?
This definition does not specify if the spell are played by the controller of the "Storm-card" or by the opponent. I read this article and it does not clarify my doubt.
I ask this because the owner of my local shop told me that Storm does not count enemy spells and he is a kind of judge.

As the answers show, this is one of many cases in which Magic cards (or rules, really) are meant to be read literally.

That is true.  The effect "Exile target permanent" is VASTLY more powerful than "Exile target permanent you control".  Unspecified target or reference are literally unspecified, so anything will trigger.
Note that judges can get it wrong too.  MtG has TONS of rules, and there are tons and tons of legacy stuff that... can happen, but are really obscure, like Enchantments that become a create and then get turned into a land and then clone happens and then all sorts of fun stuff...

Many years ago Wing Shards was a very popular card in my play group. That card teached me it's best to cast your spells in your second main phase in most cases :)

You get a copy for every previous spell, not just the ones you cast. The Storm rules (that you linked to) define Storm in rule 702.39a:

Storm is a triggered ability that functions on the stack. “Storm” means “When you cast this spell, put a copy of it onto the stack for each other spell that was cast before it this turn. If the spell has any targets, you may choose new targets for any of the copies.”

As you can see, it uses the same wording as the reminder text you quote. It does not mention who cast the previous spells, so it counts all previous spells.
Cards that care about which player did something always say so. If any trigger event, or description, or bit of text that cares about information does not mention a player, then it does not distinguish between players.

You pretty much figured this out yourself. It doesn't say the spells have to be yours, or that they have to be your opponents' (or that they can't be), so it counts all spells that have been cast.
By the way, the rule you quoted in your question appears to be from an older version of the comprehensive rules. The current version is:

702.39a Storm is a triggered ability that functions on the stack. “Storm” means “When you cast this spell, put a copy of it onto the stack for each other spell that was cast before it this turn. If the spell has any targets, you may choose new targets for any of the copies.”

If a judge (or a "kind of" judge) told you that it didn't count opponents' spells, well, they were wrong.


text:
Do bestow count toward cards that say "when [sub-type] enters on the battlefield"
Champion of the Parish gains +1/+1 "Whenever a another human enters the battlefield under your control". If I play Nyxborn Shieldmate as a bestow does it count toward this effect? I know it does not count as a creature but it is still a human is it not?

According to the definition of "Bestow" (702.102a), the card will enter as an Aura spell.

"Bestow [cost]" means "You may cast this card by paying [cost] rather than its mana cost." and "If you chose to pay this spell’s bestow cost, it becomes an Aura enchantment and gains enchant creature.

The game will remove the Creature type from the card. Since Human is a subtype of Creature and not a subtype of Aura, the card loses the Human subtype per 205.1a

"If an object's card type is removed, the subtypes correlated with that card type will remain if they are also the subtypes of a card type the object currently has; otherwise, they are also removed for the entire time the object's card type is removed."

The ability won't trigger since the card does not have the subtype Human.

I agree with your conclusion but I think the crucial rules are 205.3m and 205.3k. It's too long to post here but they state enchantment subtypes and creature subtypes, which then supports to your conclusion that as an Enchantment-Aura type it cannot have the creature subtypes. I already knew it was not a creature but your use of the phrase "creature subtypes" gave me a clue of where to look.

The other relevant rule is 205.1a: "If an object's card type is removed, the subtypes correlated with that card type will remain if they are also the subtypes of a card type the object currently has; otherwise, they are also removed for the entire time the object's card type is removed." Bestow temporarily removes the Creature type.

@murgatroid99 are you saying that "becomes an Aura" implies "loses creature and gains enchantment and Aura"?

@murgatroid99 Thanks for posting 205.1a I will update the answer.

@corsiKa Yes, I am. Unless an ability that changes types says "in addition to its types" or "still a [type. supertype, or subtype]", the other types are removed. See rule 205.1b.


text:
Does marking a card affect its legality?
I have a deck I am working on that I cannot find all the cards for yet. For use in casual play I have put in proxies that are land cards with the name of the card written on them. If I end up playing with the deck in an official tournament and forget to switch the proxies out will I still be able to use those as lands? Obviously they cannot be used as the card they are a proxy for, but does having them marked affect their legality as the card they actually are?

You can use those cards as lands, as long as they are clearly those basic lands. The tournament rules on acceptable cards says

Artistic modifications are acceptable in sanctioned tournaments, provided that the modifications do not make the card art unrecognizable, contain substantial strategic advice, or contain offensive images. Artistic modifications also may not obstruct or change the mana cost or name of the card.

However, that rule also says

The Head Judge is the final authority on acceptable cards for a tournament.

So, it's up to the Head Judge to make the final decision about whether you can use those cards as lands.
You cannot use them as the cards they are proxying in a tournament. The official proxy tournament policy says

A proxy card is used during competition to represent an Authorized Game Card that has been accidentally damaged or excessively worn in the current tournament (including damaged or misprinted Limited product) as determined solely by the Head Judge.

and

Players may not create their own proxies; they may only be created by the Head Judge.

Basically, you can't even use a proxy card in your deck unless it is replacing a card that was accidentally damaged during that tournament, and you can't use proxies that you make yourself.

You are probably ok to use those lands legally in a tournament.
For marked cards:
"A card or sleeve is considered marked if it bears something that makes it possible to identify the card without seeing its face, including scratches, discoloration, and bends."
So any writing on a basic-land (not on the back) would be fine as long as it is not excessive.  And even then, you are fine for basic lands because, "If a player is required to replace a card in his or her deck and is unable to find a replacement, the player may replace the card with a basic land card of his or her choice."  This means you will never be hurting for basic lands.

The proxy policy you link to says that you can only use a proxy if the card it's replacing has been accidentally damaged during the tournament. It also says "Players may not create their own proxies." Basically, your entire answer is incorrect.

Ah yes, that's my mistake.  The stuff about the marked cards should still be accurate, though.

I don't know why this answer keeps getting downvoted, it contains accurate and helpful information. (Particularly the part about replacing damaged cards with lands)

I know that the OP asked about "marked cards", but his description clearly covers "artistically modified" cards, which are covered by a different rule. Don't count on question authors to use good terminology. I'm not the one that downvoted, because you effectively answered the question written in the title.


text:
Can my opponent and I decide on a victory condition to avoid a draw?
Say I'm playing against a player and we finish game 2 with 5 minutes left in the round. If we draw, both of us will be knocked down, and most likely neither will be eligible for prizes.
I know bribery is against the rules, but could we agree (before the match starts) to something along the lines of "If we draw, whoever has fewer life points will concede so at least one of us can have a chance at prizes"?
As I understand it the answer will come down to if this is defined as collusion, but I'm having a hard time determining how Wizards defines it.

When you say "we" can have a chance at prizes, do you mean you're talking about deciding who will concede but splitting hypothetical prizes? Or do you simply mean that one of you will bow out and give the other a chance at it?

@Jefromi I mean one will bow out and give the other a chance at it. There will be no prize splitting, that I know is bribery and is illegal.

Bribery and Collusion do not really factor into this.  If there is no agreement (or offer) to exchange something of value for a particular match result, there is no bribery.  "Collusion" is not inherently illegal in the absence of bribery (No rule says I can't concede to my friends because they're my friends.)
You are running afoul of 'Unsporting Conduct - Improperly Determining a Winner'.  Entering into (or offering) an agreement with your opponent to choose the winner of the match by any means not included in the rules of the game is a disqualification.

Note that if, with no prior agreement, you simply choose to concede game 3 (possibly because you're lower on life, or just because you know draw or lose you're out of the running for prizes), this is fine.  Even if you're 'winning' during extra turns.  If you're in your last extra turn and you know you can't win, you can concede as a courtesy to your opponent.  Even if time hasn't even been called yet, if you look at your hand and know there's no point in playing out game three because you'll never finish it in time, you can concede to skip the pointless half-game.

As I read the player's guide (that I found here: http://blogs.magicjudges.org/whatsupdocs/mipg/4-unsporting-conduct/4-3-unsporting-conduct-improperly-determining-a-winner/ ) I'm not sure this answer is supported. The four examples they mention as against this rule are: coin flipping, dice rolling, arm wrestling, and rock-paper-scissors, and the phrase "outside-the-game" is mentioned multiple times. In fact, in single-elimination tournaments, life total is the tie-breaker.

@corsiKa In that one special circumstance yes, but the precise phrasing in the very tournament rules document that you link to is "The result of a match or game may not be randomly or arbitrarily determined through any means other than the normal progress of the game in play. Examples include (but are not limited to) rolling a die, flipping a coin, arm wrestling, or playing any other game."  The key phrase is 'normal progress of the game in play'; 'outside the game' doesn't come into it at all.

That link is out of date.  The current wording is 'a method that is not part of the current game'.  http://wpn.wizards.com/sites/wpn/files/attachements/mtg_ipg_18july14_en.pdf

I'm just saying that because the life totals are part of the game (while rock paper scissors are not) that opens the door for confusion among players who may consider life total to be a perfectly valid victory condition when they're actually committing a penalty. This confusion could easily arise even from the July 2014 edition of the IPG.

I know the question didn't explicitly ask, but as long as we're here, could you explain what you can do in this kind of situation?

@Jefromi, That would make a great separate question. Ask it!

@VolleyJosh I commented because I assumed the OP was trying to figure out what they could actually do (knowing one thing you can't do isn't terribly useful), but I guess since this got accepted it really was that specific.

What you can do in this situation is report the true result of the match.  IPG is clear on this.  Scheming to play the tournament by your own alternate rules harms other players who are in the same situation at a different table and obey the rules.  (In practice it is in fact common for players with clearly inferior board states to scoop on turn 5 of extra turns as a courtesy in this situation.  But that is different from making an agreement to play the tournament by your own rules ahead of time.)

@Affe I mentioned in other comments that I assumed the OP would be interested in things you can do when it's obvious you're going to draw but haven't actually drawn yet, i.e. the kind of turn 5 concession that you mentioned. It's not like it's a surprise when the match ends in a draw, and you'll always be left with no choice but to just write that down.

@Jefromi The rules say that you can concede at any time for any reason, but then they go on to list exceptions to this rule, such as bribery, wagering, and entering into an agreement with your opponent determine the match by means not included in the rules. So rather than ask what you can do, it's just easier to ask what you can't do.

The rules of Magic itself don't allow for players to change the win conditions. Win/lose/draw conditions are defined in the rules, and unless a tournament director decided differently, you have to play by the win/loss/draw conditions written in the regular rulebook. (And at an official MTG event, the tournament director wouldn't allow otherwise).

Can you elaborate a bit? It's still okay to decide, at the end of the match, to concede (getting nothing in return) and let the other player move on, right? And even to discuss who should concede, as long as it'd not done before the match?

@Jefromi, when you say "concede", do you mean in the sense of conceding the tournament, and not playing further matches? Or conceding the game, as in deciding to treat it as though you had lost the game? There's a difference, because once the game has ended, in a draw, you cannot then concede that game... it's already ended in a draw, too late for you to concede the game and lose.

I think the idea of the question is for one player to concede before the match ends in a draw - for example, if you run out of time and the last game goes to extra turns, you could concede the game/match at any time before the end of the last turn. (I do now notice it says "if we draw" not "if we're about to draw", but that's not that big a change to make, and I'm sure the OP would be happy to know what can be done in that case. Maybe I've misunderstood though!)

@Jefromi, I suppose in that case it is more of an issue of knowing specific tournament regulations (which I am not that knowledgeable about). It does sound like a form of collusion to me, though. But I was originally reading the question as basically saying that they would have a draw, but then based on criteria they had decided, one player would act as though he'd lost, and report that the other player actually won. This should be clearly illegal, as it would be falsely reporting the results of a game.

@Gendolkari While the rules don't allow for the players to change the win conditions, they do allow for a player to concede at any time for any reason. Without tournament rules, you could agree to flip a coin and have the loser concede the match, you could bribe, or you could just punch the other player in the face until they concede (assuming you are the stronger one).


text:
What happens to other Auras on a Creature enchanted with bestowing, when the Creature dies?
Case in point:
Ill-Tempered Cyclops has the Auras of (bestowed) Thassa's Emissary and Aqueous Form.
Then the Cyclops changes zone (returned to library, hand, gets exiled or moved to graveyard by any means necessary).
Would I be correct to presume that the Aqueous Form goes to graveyard (like Auras do) and Thassa's Emissary stays on the battlefield as a creature (like Enchantment Creatures do)?
(Questionable interpretation being that the Aqueous Form stays on the "new" creature of Thassa's Emissary)

Roughly the same question as http://boardgames.stackexchange.com/questions/14243

Aqueous Form goes to the graveyard.
It doesn't attach to the newly-a-creature Thassa's Emissary, because it wasn't enchanting Thassa's Emissary - it was enchanting the Cyclops, which has left the battlefield.
Bestow comes with exceptions that let Thassa's Emissary simply become an Enchantment Creature once it's no longer attached, but there's nothing saying that it brings with it its formerly bestowed creature's auras.

Your main answer is right, but Bestow creatures don't actually leave and re-enter the battlefield when the creature they're enchanting leaves the battlefield. Rather, as the rules you linked to say, casting such a creature for the bestow cost creates a continuous effect that makes it an Enchantment - Aura until the creature it's attached to leaves the battlefield. When that happens, it simply stops being an Aura and reverts to being a creature, so the rule causing unattached auras to leave the battlefield simply does not apply.

@murgatroid99 Whoops, thanks for pointing that out - that was bad communication on my part, I certainly didn't mean to imply they actually left and came back.

Aqueous Form goes to the graveyard.

704.5n If an Aura is attached to an illegal object or player, or is not attached to an object or player, that Aura is put into its owner's graveyard.

Thassa's Emissary becomes unattached and remains on the battlefield. (Note that it remains an Aura.)

702.102e If an Aura with bestow is attached to an illegal object or player, it becomes unattached. This is an exception to rule 704.5n.


text:
When I gain control of a creature, do I also gain control of any auras or equipment attached to it?
What would happen if I Portent of Betrayal'd a creature that had been enchanted by a bestow creature and cast a spell to give it protection from the enchantment's color on it to remove the bestowed creature?
For instance:
They have just bestowed a Nighthowler on a Asphodel Wanderer and passes the turn. I use Portent of Betrayal to take control of the Asphodel Wanderer, attack and in the second main I cast Gods Willing to give the Asphodel Wanderer protection from black. Nighthowler detaches and where does it go, my control, opponents control or graveyard?
As an additional question, in the same vein:
What if I destroyed the creature while it was on my side? So change the gods willing to a hero's downfall in the example.
Relevent (under state-based actions):

704.5n If an Aura is attached to an illegal object or player, or is not attached to an object or player, that Aura is put into its owner's graveyard.

Your opponent controls the Nighthowler.
Control of an enchantment and control of the object it enchants are independent.
Changing control of a permanent doesn't automatically change control of any Auras or Equipment attached to that permanent. Your opponent still controls the Nighthowler, even while you control the creature it enchants. And your opponent will retain control of the Nighthowler if it becomes detached from the creature you've stolen for any reason (e.g. that creature leaves the battlefield or Nighthowler can't enchant it anymore because it gains protection1), because none of the game actions described are changing control of the Nighthowler.

1 - The rules for bestow+protection are a bit poorly worded, but Rules Manager Matt Tabak has confirmed that this is the correct interpretation.

Ok, so that answers the question about hero's downfall, it would go back to the opponent's control. But what about if the creature is still in play and is just an illegal target (God's Willing)? Would rule 704.5n apply? (shown above)

Bestow overrides that rule. See rule 702.102: Bestow

I'm pretty sure rule 704.5n means that granting protection causes the bestowed creature to go straight to the graveyard rather than just becoming unattached, regardless of who controls what.

@jwodder The rules manager says otherwise.

@jwodder, See my answer.

In both case, the Nighthowler becomes a permanent[CR 702.102e], and it remains under your opponent's control.
I say "remains" because you never controlled it. Taking control of a permanent does not grant you control of any effects affecting the permanent, any equipment equipping it or any auras enchanting it. There's no reason for it to switch "to your side" just because it becomes detached.

702.102e If an Aura with bestow is attached to an illegal object or player, it becomes unattached. This is an exception to rule 704.5n.

Intersetingly, it remains an Aura

Wow, 702 broke into triple digit subsections.


text:
How does Humility affect Bestowable creatures?
Humility says each creature loses it's abilities.  So how does that work with bestowable creatures? Normally, for auras, as I understand it, it depends on the timestamp that the aura vs. the humility came into play. But bestowable creatures are creatures still I think.

Bestow creatures that are currently acting as Auras (whether on the battlefield or the stack) are not creatures.

As long as a creature card with Bestow is enchanting a creature, it is an Aura Enchantment and not a Creature. So, Humility will not affect it.
The rules for Bestow and type changing say

702.102a Bestow represents two static abilities, one that functions while the card with bestow is on the stack and another that functions both while it’s on the stack and while it’s on the battlefield. “Bestow [cost]” means “You may cast this card by paying [cost] rather than its mana cost.” and “If you chose to pay this spell’s bestow cost, it becomes an Aura enchantment and gains enchant creature. These effects last until one of two things happens: this spell has an illegal target as it resolves or the permanent this spell becomes, becomes unattached.” Paying a card’s bestow cost follows the rules for paying alternative costs in rules 601.2b and 601.2e–g.
205.1a Some effects set an object's card type. In such cases, the new card type(s) replaces any existing card types.

This means that the Bestow ability removes the Creature type from the object as long as it is in effect.
The rule for how continuous effects interact says:

613.1. The values of an object's characteristics are determined by starting with the actual object. For a card, that means the values of the characteristics printed on that card. For a token or a copy of a spell or card, that means the values of the characteristics defined by the effect that created it. Then all applicable continuous effects are applied in a series of layers in the following order:

613.1a Layer 1: Copy effects are applied. See rule 706, "Copying objects."
613.1b Layer 2: Control-changing effects are applied.
613.1c Layer 3: Text-changing effects are applied. See rule 612, "Text-Changing Effects."
613.1d Layer 4: Type-changing effects are applied. These include effects that change an object's card type, subtype, and/or supertype.
613.1e Layer 5: Color-changing effects are applied.
613.1f Layer 6: Ability-adding effects, ability-removing effects, and effects that say an object can't have an ability are applied.
613.1g Layer 7: Power- and/or toughness-changing effects are applied.

So, the static ability that turns Bestow creatures into Auras is applied before Humility's ability, so Humility will not affect those permanents. Any other relevant effects of Bestow Auras, like granting abilities to the creature they enchant, interact with Humility just like normal Auras would.


text:
Can you dredge twice for one card draw?
Say I have two Life from the Loams in my graveyard. Can I dredge twice — once for each of the Life from the Loams — when drawing my first card on my turn?
I assume the answer is no, but I figured I'd ask nonetheless.

No, you cannot.

614.6. If an event is replaced, it never happens. A modified event occurs instead, which may in turn trigger abilities. Note that the modified event may contain instructions that can’t be carried out, in which case the impossible instruction is simply ignored.
614.7. If a replacement effect would replace an event, but that event never happens, the replacement effect simply doesn’t do anything.

Once you choose to apply the first Life from the Loam's ability, you are no longer drawing a card; you are instead milling 3 and returning the card to your hand.  Thus, as soon as you apply one replacement effect (and replacement effects must be applied one after the other), there is no card draw for the other Life from the Loam to replace, and so you can't dredge twice.


text:
sacred mesa and activated abilities between untap and upkeep
Sacred Mesa says "At the beginning of your upkeep, sacrifice Sacred Mesa unless you sacrifice a Pegasus." It also has an activated ability:

1W: Put a 1/1 white Pegasus creature token with flying into play.

My question is..  so let's say you use 2W to cast it. Then on your next turn you have your untap phase and your upkeep phase. Can you create a 1/1 white Pegasus token between your untap and upkeep phases to prevent Sacred Mesa's self-sacrifice clause from triggering?

A general comment: there is never any "between" phases/steps. If there's an opportunity for anything to happen in the game, it's during a phase/step. (As for phase vs step, phases are subdivided into steps, e.g. the beginning phase has untap, upkeep, and draw steps.)

Same goes for turns. It's always someone's turn.

Simple Answer
You can save Sacred Mesa by creating a Pegasus in response to Sacred Mesa's triggered ability.
Detailed Answer
Strictly speaking, you can't create a Pegasus between your untap step and your upkeep step because you don't have an opportunity to do so. The beginning of your turn has the following sequence of events:

Your untap step:

You untap your permanents

Your upkeep step:

Abilities that trigger at the beginning of the upkeep go on the stack
You gain priority.

You can only cast spells and activate abilities when you have priority, so the first opportunity to do so is during your upkeep, when the ability is on the stack though. This still lets you save your Mesa, though, because you can respond to the triggered ability by activating Mesa's activated ability. Because the activated ability went on the stack last, it will resolve first, and you will have your Pegasus before you need to sacrifice one.

You can save Mesa, but not in the way you specified.
You can't activate the ability before the triggered ability triggers, but you can save Mesa by creating a Pegasus in response to the Mesa's triggered ability.

Mesa's triggered ability triggers as the Upkeep Step starts.
Mesa's triggered ability is placed on the stack.
In response, you activate Mesa's activated ability.
Mesa's activated ability resolves:

Put a 1/1 white Pegasus creature token with flying into play.

Mesa's triggered ability resolves:

You sacrifice the newly created Pegasus (or Mesa).


text:
Pandemonium and Muscle Sliver
Pandemonium is an enchantment that says "Whenever a creature enters the battlefield, that creature's controller may have it deal damage equal to its power to target creature or player of his or her choice."  Muscle Sliver is a 1/1 creature that gives all Slivers (itself included) +1/+1.
So if you have no other Slivers in play, does Pandemonium do 1 point of damage or 2 points of damage when Muscle Sliver comes into play?

There is never a moment the Muscle Sliver isn't giving itself +1/+1 when it's on the battlefield.

Pandemonium's triggered ability checks the power of the creature when it resolves, not when it triggers. A ruling on Pandemonium says the same thing.

The triggered ability does not check the creature's power until the ability resolves. If the creature is not on the battlefield when the ability resolves, it does damage equal to the power of the creature right before it left the battlefield.

By the time the ability resolves, Muscle Sliver is already on the battlefield, and his power is being modified by his own ability. You may have it deal 2 points of damage.
Still not convinced?
There are cases when a creature's power is checked when an ability triggers and when it resolves. To illustrate this, consider the case where we play Muscle Sliver when we already have an Experiment One on the battlefield. Will Muscle Sliver trigger evolve?
The answer is yes. This is because of rule 611.3c (although it is mentioned in a few places).

611.3c Continuous effects that modify characteristics of permanents do so simultaneously with the  permanent entering the battlefield. They don’t wait until the permanent is on the battlefield and then change it. Because such effects apply as the permanent enters the battlefield, they are applied before determining whether the permanent will cause an ability to trigger when it enters the battlefield.

Maybe add a note about last known information if the creature is gone when the ability resolves?

Also, because it uses the power of the creature as the Pandemonium ability resolves, you could buff your creature with Giant Growth for example while the Pandemonium trigger is on the stack to deal 5 damage with your Muscle Sliver

@HaoYe Added your note (see the expanded ruling on Pandemonium).

Muscle Sliver will deal 2 damage to a creature or player due to Pandemonium's ability.
Pandemonium's ability is a triggered ability that triggers when a creature enters the battlefield. So when Muscle Sliver enters the battlefield, the triggered ability is put on the stack and you choose what creature or player to target. At this point Muscle Sliver is already in play, so its power is 2 due to its own static ability. Then the triggered ability resolves, and Muscle Sliver deals 2 damage to the ability's target.


text:
Bestow and Intimidate - what color do I need?
What color do I need to block a bestowed creature which got intimidate? Example: I cast a black bestow aura which grants intimidate on a blue creature. Do I need a blue creature to block it?

Yes, only blue (or artifact) creatures can block it.
Cavern Lampad unfortunately doesn't include reminder text for Intimidate, but if it did, it would say "This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.". It's granting the ability to your blue creature, so it's that creature's color that matters. Yes, Cavern Lampad does also itself have intimidate, but that's irrelevant; you're attacking with the enchanted creature, not the Lampad.
Sometimes Auras do actually have abilities, as opposed to granting abilities to the creatures they enchant. For example, Crown of Flames has the firebreathing ability ({R}: Enchanted creature gets +1/+0 until end of turn), while Dragon Mantle gives that ability to the creature it enchants ("Enchanted creature has {R}: This creature gets +1/+0 until end of turn."). But in the case of intimidate, it has to be like this, with the creature, not the aura, having the ability. You're attacking with the creature, not the aura, so for intimidate to do anything, the creature has to have it!

Now we just need an aura that says "Enchanted creature is blue" - mwahaha

Yes, you need a blue and/or artifact creature to block a blue creature enchanted with Cavern Lampad
From the Basic Rule book

Intimidate

A keyword ability seen on creatures. A creature with intimidate can’t be blocked except by creatures that share a color with it and/ or artifact creatures. For example, a red creature with intimidate could be blocked by a red creature, a red-and-green creature, or any artifact creature. Intimidate only matters when the creature with the ability is attacking.

From the Comprehensive Rules

702.13. Intimidate

702.13b A creature with intimidate can’t be blocked except by artifact creatures and/or creatures that share a color with it. (See rule 509, “Declare Blockers Step.”)


text:
Can Etrata 'hit' commanders and count them toward game loss?
Etrata, the Silencer has this ability:

Whenever Etrata deals combat damage to a player, exile target creature that player controls and put a hit counter on that card. That player loses the game if they own three or more exiled cards with hit counters on them. Etrata’s owner shuffles Etrata into their library.

It used to be the case that it would be useless to exile a commander this way. However as of June 7 2020, MTGCommander.net announced a new rule for sending your commander to the command zone from graveyard or exile that now uses state-based actions:

If a commander is in a graveyard or in exile and that card was put into that zone since the last time state-based actions were checked, its owner may put it into the command zone.

(The hand/library rule is still a replacement effect.)
Under these rules, can I exile somebody's commander with Etrata and count it toward them potentially losing the game?

Yes, you can exile a player's commander this way now, and you can cause that player to lose the game this way if it's the third card of theirs you exiled with a hit counter. This happens even if the player wants to move their commander to the command zone—because they lose the game before they get the option to do that. However, it still won't be helpful to pick their commander for the first or second 'hit'.
The events now unfold like this:

Etrata deals combat damage to a player.
Her ability goes on the stack. You choose their commander as the target.
(Let's assume players do nothing in response and let the ability resolve.)
Etrata's ability resolves. As part of resolution, the target creature is exiled with a hit counter on it. Then, that creature's owner loses if they have three or more cards in exile with hit counters on them. Then, Etrata gets shuffled into her owner's library.
Now that Etrata's ability has finished resolving, state-based actions are checked. As part of this, the player whose commander was just exiled has the choice to move their commander to the command zone:

If they choose to move their commander, it vanishes from exile and is now in the command zone without a hit counter on it. It will not count toward future 'hits' anymore.
If they choose to leave it in exile, it will stay there with a hit counter on it.

You'll see that during ability resolution their commander is still in exile. This means if you've exiled two other cards and then the player's commander, that player now loses the game. They don't have the option yet to move their commander out of exile.
If you exile their commander for the first or second hit, then they won't lose the game and can subsequently move the commander out so it won't count as a hit for the next time. So that's still not a good choice.
What if I have multiple Etratas, or I copy her ability with Strionic Resonator?
State-based actions still get checked between any two abilities resolving. If you want to pull this off, Etrata still needs to exile their commander for the last 'hit' and not the first or second. This means target the commander with the first such trigger that goes on the stack.
This would work:

Attack with three Etratas (using Helm of the Host) that all deal combat damage to the player.
Because the abilities go on the stack simultaneously, you choose the order. Choose their commander for the first ability to go on the stack, then two other creatures for the next two.
The topmost Etrata ability resolves, exiles one of those other creatures, and doesn't cause the player to lose the game.
The next Etrata ability resolves doing the same with another creature.
The last Etrata ability resolves, exiles their commander, and causes them to lose the game.

This would also work:

Have a card owned by that player in exile with a hit counter on it from a previous turn.
Attack with one Etrata and deal combat damage to that player.
Etrata's ability goes on the stack — choose their commander for the target.
Using Strionic Resonator, copy the ability and choose another creature for the target. This goes on the stack on top of the original trigger.
The copied ability resolves first, exiling the other creature for the second 'hit'.
The original ability resolves next, exiling their commander for the third 'hit' and causing them to lose the game.

However, if you choose the commander for the first trigger that resolves, the player will be able to move their commander out of the command zone before the next ability resolves. This means the next ability won't count that 'hit'.

I might be missing something, but is this new method of dealing with the commander replacing the old "if your commander would go to the graveyard/exile you may put in your command zone instead" rule or is this just a "IF" your commander was put into the graveyard/exile "AND" you didn't move it this is when you can choose to move it next, type of rule clarification?

@QuestioningSquidly It's replacing the old rule, not an addition. You can read more here: https://boardgames.stackexchange.com/a/27705/5573


text:
Can I block with a previously bestowed creature?
When a creature enchanted with a bestow creature dies while blocking a creature, the bestow enchantment becomes a creature. Can that creature block in the same combat, even though all the blockers have already been declared?

No, as you've said in your question, all of the blockers have already been declared. There's not another opportunity to declare blockers, especially not after combat damage has been dealt!
The steps of combat are:

beginning of combat
declare attackers
declare blockers
combat damage
end of combat

Your creature presumably doesn't die until the combat damage step. You can't go back to the declare blockers step to declare a new blocker, and it wouldn't even make any sense to: by the time your blocker takes damage and dies, combat damage dealt to you by unblocked creatures has already happened too, so there's nothing left to accomplish by blocking.
And if your creature dies after blockers are declared, but still in the declare blockers step - destroyed by an instant, perhaps - it's of course still too late. If on the other hand it dies before blockers are declared, the bestowed-aura-turned-creature can certainly block.

Not-so-minor nitpickery: it's very possible that the 'host' creature was killed after blockers were declared (e.g. by Doom Blade or the like).  The bestowed aura that falls off still can't block in this case, of course.

@StevenStadnicki I added something to mention that, but I do think it's pretty minor - I don't think it's what the OP meant given the phrasing, and it doesn't really change the substance of the answer.


text:
Why is it called "Chinese Checkers"?
It is not a Checkers variant, nor did it originate in China, how could this name possibly make sense?

You should really do at least a little research before you ask a question like this. If you Google the title of your question verbatim, you get a small info box that contains your answer, which is contained in the first hit.

@murg I honestly tried and couldn't find anything...

How is this question Too Broad? There is actually a button on this screen that says "This question shows little research effort." if you hover over it.

There seems to be surprisingly little information about the origin of the name "Chinese Checkers". The game itself was first released in 1892 in Germany as "Stern-Halma" (literally "Star-Halma"), indicating that it was a variation of Halma that was played on a star-shaped board. But there doesn't seem to be any solid information about why the name "Chinese Checkers" became associated with the game.
The only thing that I could find was a history of the game on PlayChineseCheckers.com, which despite sounding authoritative is written by an anonymous author who doesn't back its claims (not to mention has a website that looks like a GeoCities page from the 90s) and so the following passage should be taken worth a grain of salt:

The first Chinese Checkers game to be published in the United States was 'Hop Ching Checkers' in 1928 by J. Pressman & Co. This was exact the same game as the 1892 Star-Halma. The brothers Bill and Jack Pressman made up the name 'Chinese Checkers' during or shortly after 1928. The game was given a Chinese name and theme in keeping with the current interest in all things oriental (among them the discovery of King Tut's tomb in 1922 and the 'mah jongg' game that was introduced in 1923)

I'd like to stress again that despite this being a really solid-sounding explanation, the author is anonymous and there are no sources to back up this claim, so it's not clear whether or not this is true.
After a great deal of searching, I did not manage to find a more authoritative source on the subject, so the true origins of why the game is called "Chinese Checkers" may remain a mystery.

Here is a more authoritative source that has many images of old versions of Chinese checkers: http://thebiggamehunter.com/games-one-by-one/halma/ (Bruce Whitehill is a boardgame historian/collector)

Pressman also claim they "[made] Chinese Checkers into a craze that swept the nation in the 1920s": http://www.pressmantoy.com/about/

Another article with some more quotes from Bill Pressman on the BGH site: http://thebiggamehunter.com/games-one-by-one/chinese-checkers/

In the old days, when something was unusual or "backwards" or just plain weird, it was referred to as "Chinese". Hence the game not resembling checkers in the slightest, it was coined "Chinese checkers".


text:
Losing Control of Bestowed Enchantment Creatures
I've been playing Magic for about six months and thought I had a decent handle on how things work until I ran into the following problem:
Set-up:
I was playing mono black devotion against blue-green control. I bestowed Herald of Torment onto Pharika Chosen. At the end of my turn, my opponent (in control of Prophet of Kruphix) flashed in a Siren of the Fanged Coast. I chose not to pay the tribute, so my opponent took my Pharika Chosen with Herald of Torment attached.
Question:
If I kill Pharika Chosen while my opponent controls it, when Herald of Torment becomes a creature again do I regain control of Herald of Torment, or does my opponent retain possession of it?

possible duplicate of When I gain control of a creature, do I also gain control of any auras or equipment attached to it?. I edited the title on the older one to hopefully prevent this question from being asked a third time.

"Could not pay the tribute"?  Did you mean "Chose not to pay the tribute", or do you think you need to move +1/+1 counters from other creatures or something?

My mana was tapped and I could not pay the tribute of 3.

@IlMatto0; Tribute does NOT mean what you think it does! The reminder text below the Tribute keyword clarifies this, but Tribute 3 means that your opponent can choose to have it enter the battlefield with 3 +1/+1 counters on it... NOT that your opponent can choose to pay 3 mana!

Thanks Gendolkari! Wow. My friend and I have been using it wrong for a long time. I feel dumb.

Your opponent never had control of Herald of Torment. When he took your creature, he only took the creature; he did not take control of any auras (or equipment) attached to it. So in this case, he would have control of a creature that has an aura that you control on it. This means that the creature would have +3/+3 and flying like usual; and YOU would lose 1 life per turn, not him.
So when the Bestow falls off and becomes a creature, it will be a creature under your control. It always was under your control.


text:
Cards changing mana color
What cards across all sets allow the utilization of mana, either colorless or otherwise, as colored mana of another color?
One early example with an unlimited  1:1 ratio:

Sunglasses of Urza
  Continuous Artifact: White mana in your mana pool can also be used as red mana.

What other cards have similar abilities?

I have a feeling that there will be many cards in this list, so please comment to suggest how to organize this list. My initial thought is by in:out ratio, eg if there were a card that read 1U: add B to your mana pool, that would be a 2:1 ratio.

There are two kinds of cards with this description. There are cards like the Sunglasses that let you use mana to pay for costs of a different color, which are quite rare. Then there are cards that let you pay mana of one color to get mana of another color, and those are very common.

magiccards.info offers a wide range of query option. You need to try it out.

There are nine cards that allow you to spend mana as though it were another color:

Mycosynth Lattice lets you spend mana as though it were mana of any color without restriction.
Daxos of Meletis and Psychic Intrusion allow you to cast a spell from an opponent's library, and allow you to spend mana as though it were mana of any color when paying that spell's cost.
Celestial Dawn and False Dawn both let you tap your lands for white mana and spend white mana as though it were mana of any color. False Dawn additionally makes any other mana you generate white.
North Star lets you spend mana as though it were mana of any color for a single spell, and Unexpected Potential lets you spend mana as though it were mana of any color for spells with a chosen name.
Quicksilver Elemental lets you spend blue mana as though it were mana of any color for its own abilities (which it copies from other creatures).
Sunglasses of Urza lets you spend white mana as though it were red.

There are also 58 cards that allow you to spend mana to get colored mana. I'm not going to list all of them, but here are some highlights:

Bog Initiate filters an arbitrary amount of mana into black mana.
Farrelite Priest filters an arbitrary amount of mana into white mana, with the caveat that you have to sacrifice it if you activate the ability 4 or more times in one turn. Initiates of the Ebon Hand does the same for black mana.
Orochi Leafcaller filters an arbitrary amount of green mana into mana of any color. Nomadic Elf does the same, but at an additional cost of one mana per mana generated.
A cycle of cards like An-Havva Township, which let you tap and pay one mana for one color, or tap and pay two mana for your choice of two other colors.
A cycle of lands from Eventide like Cascade Bluffs, which let you tap and pay one mana in your choice of two colors to get two mana in any combination of those colors.
A cycle of lands like Darkwater Catacombs, which let you tap and pay one mana to get one mana in each of two colors.
The Ravnica guild signets, like Boros Signet, which let you tap and pay one mana to get one mana in each of the guild's two colors.
The land Crystal Quarry, which lets you tap and pay 5 mana to get one mana of each color.


text:
Remove bestow target, does it become a creature?
If my opponent was to cast bestow onto a creature, and i then remove the creature, does the bestow get countered and go to the graveyard, or does it become a creature?

It becomes a creature, because the rules make a special exception for bestow. Even though you've cast your creature with bestow as an aura spell, when it resolves, it can end up as an aura or a creature. From the bestow section of The Mechanics of Theros:

If the target creature leaves the battlefield after you cast a card with bestow as an Aura but before the spell resolves, the Aura spell will resolve as an enchantment creature rather than being countered like a normal Aura spell. If the target creature is still on the battlefield when the Aura spell resolves, it resolves as an Aura enchanting that creature.

And the specific rules for this case:

702.102a ... These effects [turning it into an Aura spell] last until one of two things happens: this spell has an illegal target as it
resolves or the permanent this spell becomes, becomes unattached. ...

702.102d As an Aura spell with bestow begins resolving, if its target is illegal, the effect making it an Aura spell ends. It continues resolving as a creature spell and will be put onto the battlefield under the control of the spell’s controller. This is an exception to rule 608.3a.

(Rule 608.3a is the rule about how aura spells normally resolve, which would cause a normal aura spell to go to your graveyard at this point.

That's what I call a reminder rule. If you read the definition of Bestow (702.102a), you'll see it says it stops becoming an Aura enchantment if the target becomes illegal. At that point, you're left with an Enchantment Creature on the stack, while will resolve as any other Enchantment and/or Creature.

@ikegami Well, okay, 702.102a and 702.102d say the same thing, but 702.102d spells it out in more detail, so it still seems pretty useful here. (And tiny nit: it says "as it resolves", so I don't think you ever have an Enchantment Creature spell on the stack waiting to resolve.)

I wasn't disagreeing. I was just adding more info.

Usually when an aura card is being cast targeting a creature, it would become countered and put in the graveyard when the creature isn't there anymore. However, bestow auras are an exception because they will just enter the battlefield as a creature in that case.

why the downvote? the answer is basically the same as Jefromi's only with less details

Short answer is yes, the spell goes to the graveyard if there is no creature for it to bestow. This means you need an instant removal spell like doomblade, lightning strike etc... and must cast IN RESPONSE to the bestow being cast.

This is true of normal auras, but not bestow. There are special rules for bestow, letting it resolve as a creature if it no longer has a target to enchant. See for example bestow in the mechanics of Theros summary.


text:
Can Teysa, Orzhov Scion sacrifice itself and still use its 2nd ability?
What happens if I sacrifice Teysa, Orzhov Scion along with two other "white and black" creatures (in order to remove another creature from the game) - do I still get my 2 spirit tokens from the other two sacrificed white and black creatures, even though Teysa as well was sacrificed at the same time?
Or is it that when Teysa is sacrificed along with the other two, its 2nd ability doesn't count anymore?

You will still get the 2 spirit tokens. This is because when creatures die (are put into the graveyard from the battlefield), the game checks what the state of things was just prior to the creatures leaving the battlefield to see if there is anything that needs to trigger.

603.6d Normally, objects that exist immediately after an event are checked to see if the event matched any trigger conditions. Continuous effects that exist at that time are used to determine what the trigger conditions are and what the objects involved in the event look like. However, some triggered abilities must be treated specially. Leaves-the-battlefield abilities, abilities that trigger when a permanent phases out, abilities that trigger when an object that all players can see is put into a hand or library, abilities that trigger specifically when an object becomes unattached, abilities that trigger when a player loses control of an object, and abilities that trigger when a player planeswalks away from a plane will trigger based on their existence, and the appearance of objects, prior to the event rather than afterward. The game has to "look back in time" to determine if these abilities trigger.

@Klausi, If this answers your question, please check the mark next to it. (If not, say what's lacking.) Welcome to B&CG!

Actually, the creatures don't go to the graveyard at the same time because of rule 601.2g, so rule 603.6d doesn't apply here.

I would think that "Sacrifice 3 creatures" counts as all 1 cost, not 3 separate costs to be paid in any order. But I could see it either way. 601.2g isn't clear on this, do you have another reference?

Actually, 603.6d is still needed, because the triggered ability isn't put on the stack in the middle of paying the costs anyway. It is added to the stack after Teysa's ability.

If my answer were right (I now agree that it isn't, so I have deleted it), 603.6d would not be relevant, because the time when an ability is put on the sack is not the same that the time when an ability triggers, and 603.6d is only about the latter.

@Pablo, good point.


text:
Gaining control of a creature while an Aura targeting it is on the stack
It's my opponent turn.  I have Prophet of Kruphix on the battlefield, which means I can play creatures as though they had flash.
My opponent plays Boonweaver Giant and chooses Spectra Ward, which goes on the stack as triggered ability (?)
I play Hypnotic Siren with bestow to gain control of Boonweaver Giant in response to the triggered ability.  (I can do this during my opponent's turn because I control Prophet of Kruphix.)
Does that mean that the stack looks like this?
        TOP
    Hypnotic Siren   \
                     |
  / Spectra Ward     | 1
2 |                  |
  \ Boonweaver Giant /

        BOTTOM

Will I gain control of Boonweaver Giant, and then it gets the Spectra Ward Aura under my control?
Can someone tell me whether there is a mistake in this play?
The rulings on Hypnotic Siren say:

Gaining control of a creature doesn’t cause you to gain control of any Auras or Equipment attached to it.

which does not apply to this situation because Boonweaver Giant does not have any Auras attached to it when I gain control of it with Hypnotic Siren.

First, if Boonweaver Giant's triggered ability is on the stack, then Boonweaver himself is not on the stack. He has already entered the battlefield. Second, Spectra Ward should never have been placed on the stack. Boonweaver Giant's triggered ability is what actually gets placed on the stack. Your opponent doesn't have to make a decision until it resolves.
With these corrections in mind, here is what your stack actually looks like:

Hypnotic Siren (TOP)
Boonweaver Giant's triggered ability (BOTTOM)

Hypnotic Siren resolves. You gain control of Boonweaver Giant. Next, Boonweaver Giant's ability resolves. Your opponent may search for an aura and attach it to Boonweaver Giant. He may choose not to. If he does, he will control the aura attached to Boonweaver, and you will control Boonweaver.

The opponent may still search for Spectra Ward, which will then enchant Boonweaver. Since it has protection from all colours, Hypnotic Siren will be detached again and be a 1/1 flyer under OP's control. Boonweaver will be a 6/6 with protection from all colours under opponent's control.

@M.Herzkamp Spectra Ward says "This effect doesn't remove auras." Hypnotic Siren is an aura. It won't be removed.

Oh, my bad. Didn't read that right. I had something like [mtg:Floating Shield] in mind, which reads Enchanted creature has protection from the chosen color. This effect doesn't remove Floating Shield. (I removed my other comment.)

Casting Hypnotic Siren on Boonweaver Giant will not give you control of Spectra Ward.  However, this doesn't matter, as Spectra Ward will continue to give its bonus to Boonweaver Giant anyway, and (unlike, say, Curiosity) this bonus does not depend in any way on who controls Spectra Ward.
Also, your understanding of how the stack works here is flawed.  If you intend to cast Hypnotic Siren after the Spectra Ward enters the battlefield, then the correct order of events is:

Your opponent casts Boonweaver Giant.

Boonweaver Giant resolves and enters the battlefield (and thus is no longer on the stack).

Boonweaver Giant's "enters the battlefield" ability triggers and goes on the stack.  Your opponent does not search for an Aura at this time.

Boonweaver Giant's ETB trigger resolves.  At this point, your opponent searches his or her library for an Aura and puts it onto the battlefield attached to Boonweaver Giant.  This happens all at once.  The Aura is never on the stack.

Due to the Spectra Ward, Boonweaver Giant now has protection from blue, and so you cannot cast Hypnotic Siren on it.

If you instead cast Hypnotic Siren before Spectra Ward enters the battlefield, that will have to take place immediately after step 3.  At that point, you will have no knowledge of what Aura your opponent will search for, and by the time your opponent does search, you will control the Boonweaver Giant and (because its ability says "may") your opponent (who still controls the ETB ability) has the option to not search for an Aura to place on the Giant — or to search for an Aura that negatively affects you (like a Control Magic to steal the Giant back!).

@M.Herzkamp Spectra Ward says "This effect doesn't remove auras." Hypnotic Siren is an aura. It won't be removed.

You cannot bestow enchantments during your opponents turn.  When you bestow an enchantment creature it is considered an aura.  Prophet only allows you to cast creature spells.
Card Text:
Bestow 5BlueBlue (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying.

This is incorrect.

jwodder provided the link with the full reasons, but to put it simply, you've misread Prophet of Kruphix. It says "You may cast creature cards as though they had flash." not creature spells as you said.


text:
Exiling Creatures: When is the card face up and when face down?
An opponent's Banisher Priest exiled my Goblin Shortcutter.
As I was reading some rules, I came across the fact that in some situations exiled cards face upwards and sometimes downwards.
What factor determines whether the card gets exiled face up or face down? The text on the card?

If the ability says to exile the card face down, you exile it face down. Otherwise, you exile it face up. Banisher Priest doesn't say to exile the creature face down, so you exile it face up. Rule 406.3 says

Exiled cards are, by default, kept face up and may be examined by any player at any time. Cards "exiled face down" can't be examined by any player except when instructions allow it. However, once a player is allowed to look at a card exiled face down, that player may continue to look at that card as long as it remains exiled, even if the instruction allowing the player to do so no longer applies. A card exiled face down has no characteristics, but the spell or ability that exiled it may allow it to be played from exile. Unless that card is being cast face down (see rule 707.4), the card is turned face up just before the player announces that he or she is playing the card (see rule 601.2).

One thing to keep in mind is that the point of exiling a card face down is to keep players from knowing what it is. It wouldn't make sense to exile a card face down if everyone already knows what it is. The only abilities that say to exile face down are abilities that exile from hidden zones: the hand and the library.

Well, I suppose (theoretically) exiling a card face-down from a public zone could affect interactions with Pull from Eternity or Riftsweeper. Also, if no player had permission to look at the face-down exiled card, exiling a Commander face-down from a public zone with such an effect wouldn't give the Commander's owner permission to return it to the Command zone. As you say, there are no such cards currently in existence, though.

They wouldn't print cards that exile from public zones face down just because of the interaction with a couple of other cards. It would make sense in too few cases and would confuse people too much. Also, you're wrong about the commander thing. Rule 903.13 says that in that case, the Commander returns to the command zone (I can't imagine a card that exiles face down from a public zone without allowing anyone to look at it).

If a commander is exiled face-down and nobody may look at the face-down card, you can't send the commander back to the command zone. Even if you know the face-down card is the commander (eg, Memory Lapse the commander with Future Sight in play, then tap Pyxis of Pandemonium). If they printed a card that exiled face-down from a public zone and didn't give permission to look at the face-down card, you couldn't replace the exile with sending to the command zone. If anybody has permission to look at the face-down card, the owner gets the opportunity to replace the event.

See my parenthetical for a response to that point.

It's all theoretical, anyway, and getting a bit off-topic. :)