Emrakul, the Promised End

You also can’t make any choices or decisions for the player that would be called for by the tournament rules (such as whether to take an intentional draw or whether to call a judge).

An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered or otherwise leaves the stack without resolving.

The card types that could appear in your graveyard are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Supertypes (such as legendary and basic) and subtypes (such as Human and Equipment) are not counted. The maximum discount that Emrakul’s own ability can provide is {9}.

Controlling a player doesn’t allow you to look at that player’s sideboard. If an effect instructs that player to choose a card from outside the game, you can’t have that player choose any card.

While controlling another player, you can see all cards in the game that player can see. This includes cards in that player’s hand, face-down cards that player controls, and any cards in that player’s library the player may look at.

Protection from instants means that Emrakul can’t be the target of instant spells or activated or triggered abilities from instant cards, and damage that would be dealt to it by instant spells or cards is prevented. Instant spells may still affect it in other ways; for example, it would still receive the bonus from Rally the Peasants.