3) Search for an equipment, and exile it. It never gets on the battlefield.
"It's in one sentence" is not relevant. If you want a rule of thumb, use this: one verb = one action. Even if they are on the same line or sentence or phrase, they are separated actions.
Giant's ability wants to do the following actions, in order: search; then put; then attach; then shuffle. Opposition Agent exiles the cards that is found during the "search" action, preventing the "put on the battlefield" action. The "attach" action also becomes impossible. Then, the player performs the "shuffle" action.
The cards found in the search will be exiled rather than be put wherever the spell or ability tells the opponent to put them after finding them. Any other effects the spell or ability has will still apply. If such an effect refers to the found cards, it can see them in exile.
(2020-11-10)
Wulfgar of Icewind Dale's last ability affects only triggered abilities with conditions that are directly related to attacking, such as "whenever this creature attacks" or "whenever you attack with one or more creatures." It does not affect triggered abilities with other trigger conditions, such as "whenever this creature becomes tapped."
So yes, it affects "whenever you attack" abilities. You attacking with a creature caused Overwhelming Instinct to trigger, so Wulfgar's static ability (his is not an "effect trigger") causes Instinct's ability to trigger twice.
You don't choose a land beforehand for Crack the Earth; you choose and sacrifice one land you have when Crack the Earth resolves. You don't have a window of time between choosing a land to sacrifice, and actually sacrificing it.
So you either sacrifice Ghost Quarter for Crack the Earth and not for its ability; or you use Quarter's ability in response, and end up having to sacrifice some other land to Crack the Earth.
The activated ability, when it resolves, would give to Mairsil the triggered ability "Whenever equipped creature deals combat damage to a player, that player loses the game". In order for this triggered ability to work, Mairsil would need to be an equipment equipped to a creature. Mairsil being a creature with an equipment wouldn't, ahem, cut it.
We don't yet have the full rules that explain how a d20 ability such as The Deck's works. My informed guess is that it's all a single activated ability, so it would work with Mairsil normally.
Progenitus has a static ability with a replacement effect ("if X would happen, Y happens instead"). It applies at the moment Progenitus would be put on the graveyard: it goes to the library instead. This means Progenitus is not, at any point, actually on the graveyard. So it was not a creature card that was "put into a graveyard this way" for Selection.
Kozilek, on the other hand, has a regular triggered ability that uses the stack ("when X happens, Y also happens"). This means Kozilek first do goes onto the graveyard, then its ability triggers. The ability can't even be put on the stack while Necromantic Selection is still resolving, so Kozilek is still on the graveyard and can be selected and returned to the battlefield. The player still gets to shuffle whatever else is on their graveyard when the ability resolves later, though.
Shouldn't it be "Beth CANNOT cast an overloaded Cyclonic Rift" in the reply above? Since Alvin controls the Void Winnower that says in part "Your opponents can't cast spells with even mana values," Cyclonic Rift with its mana value of two would not be legal for any other player to cast, overloaded or not.
Chapter abilities are triggered abilities. They go on the stack.
714.2. A chapter symbol is a keyword ability that represents a triggered ability referred to as a chapter ability.
714.2a. A chapter symbol includes a Roman numeral, indicated here as "{rN}." The numeral I represents 1, II represents 2, III represents 3, and so on.
714.2b. "{rN}--[Effect]" means "When one or more lore counters are put onto this Saga, if the number of lore counters on it was less than N and became at least N, [effect]."
714.2c. "{rN1}, {rN2}--[Effect]" means the same as "{rN1}--[Effect]" and "{rN2}--[Effect]."
I’ve been looking around everywhere and haven’t been able to find any real answers, so maybe someone can help me out. If I attach Assault Suit to Yidris, and someone else deals combat damage with him, do my spells gain cascade, or do theirs?
"You" on a permanent means "this permanent's controller". So Yidris's current controller, not you, gains Cascade on their spells.
1. No. The opponent gains two extra turns, for a total of three turns. You control them during the first one only.
When the first instance of Emrakul's ability resolves, it sets up a continuous effect that gives you control of the opponent during their next turn, and then gives them an extra turn to be had after that turn.
When the second instance of Emrakul's ability resolves, it sets up another continuous effect that gives you control of that same opponent during their next turn. Their "next turn" is the same for both effects, so both effects are redundant. Then the opponent gains another extra turn to be had after that turn during which you control them twice.
2. If you leave the game, the continuous effect giving you control of the player immediately ceases. The player keeps playing their turn, now fully in control of themselves.
Emrakul doesn't cause turns to end earlier. Both the turn control and the extra turn effects wait until the current turn ends the regular way.
In that case, if I choose to let cowardice's ability go first, can't the glasskite counter cowardice's ability then? And that would mean the ability/spell my opponent plays is the second ability/spell so that one can't be countered.
EDIT: nevermind that doesn't make sense cowardice keeps on triggering of course
The M19 planeswalkers are Ajani, Tezzeret, Liliana, Sarkhan and Vivien. Of those, Tezzeret and Liliana are aligned with Bolas, while Sarkhan and Vivien have reasons to oppose him, so my guess is Ajani is recruiting them.
"It's in one sentence" is not relevant. If you want a rule of thumb, use this: one verb = one action. Even if they are on the same line or sentence or phrase, they are separated actions.
Giant's ability wants to do the following actions, in order: search; then put; then attach; then shuffle. Opposition Agent exiles the cards that is found during the "search" action, preventing the "put on the battlefield" action. The "attach" action also becomes impossible. Then, the player performs the "shuffle" action.
The cards found in the search will be exiled rather than be put wherever the spell or ability tells the opponent to put them after finding them. Any other effects the spell or ability has will still apply. If such an effect refers to the found cards, it can see them in exile.
(2020-11-10)
So yes, it affects "whenever you attack" abilities. You attacking with a creature caused Overwhelming Instinct to trigger, so Wulfgar's static ability (his is not an "effect trigger") causes Instinct's ability to trigger twice.
You don't choose a land beforehand for Crack the Earth; you choose and sacrifice one land you have when Crack the Earth resolves. You don't have a window of time between choosing a land to sacrifice, and actually sacrificing it.
So you either sacrifice Ghost Quarter for Crack the Earth and not for its ability; or you use Quarter's ability in response, and end up having to sacrifice some other land to Crack the Earth.
We don't yet have the full rules that explain how a d20 ability such as The Deck's works. My informed guess is that it's all a single activated ability, so it would work with Mairsil normally.
Progenitus has a static ability with a replacement effect ("if X would happen, Y happens instead"). It applies at the moment Progenitus would be put on the graveyard: it goes to the library instead. This means Progenitus is not, at any point, actually on the graveyard. So it was not a creature card that was "put into a graveyard this way" for Selection.
Kozilek, on the other hand, has a regular triggered ability that uses the stack ("when X happens, Y also happens"). This means Kozilek first do goes onto the graveyard, then its ability triggers. The ability can't even be put on the stack while Necromantic Selection is still resolving, so Kozilek is still on the graveyard and can be selected and returned to the battlefield. The player still gets to shuffle whatever else is on their graveyard when the ability resolves later, though.
You're correct, I forgot the negative.
Beth can't cast Cyclonic Rift overloaded.
It does not.
Oveloaded Cyclonic Rift is still a Mana Value 2 spell.
714.2. A chapter symbol is a keyword ability that represents a triggered ability referred to as a chapter ability.
714.2a. A chapter symbol includes a Roman numeral, indicated here as "{rN}." The numeral I represents 1, II represents 2, III represents 3, and so on.
714.2b. "{rN}--[Effect]" means "When one or more lore counters are put onto this Saga, if the number of lore counters on it was less than N and became at least N, [effect]."
714.2c. "{rN1}, {rN2}--[Effect]" means the same as "{rN1}--[Effect]" and "{rN2}--[Effect]."
Activated abilities are written as [cost]: [effect]
Triggered abilities usually go [when/whenever/at] [event], [effect]
"You" on a permanent means "this permanent's controller". So Yidris's current controller, not you, gains Cascade on their spells.
When the first instance of Emrakul's ability resolves, it sets up a continuous effect that gives you control of the opponent during their next turn, and then gives them an extra turn to be had after that turn.
When the second instance of Emrakul's ability resolves, it sets up another continuous effect that gives you control of that same opponent during their next turn. Their "next turn" is the same for both effects, so both effects are redundant. Then the opponent gains another extra turn to be had after that turn during which you control them twice.
2. If you leave the game, the continuous effect giving you control of the player immediately ceases. The player keeps playing their turn, now fully in control of themselves.
Emrakul doesn't cause turns to end earlier. Both the turn control and the extra turn effects wait until the current turn ends the regular way.
Even if you counter the spell with Cancel, Cowardice's ability still returns the creature to hand.
Cowardice's ability does not target the creature.