Emrakul, the World Anew

Every prior Emrakul has been a wall you build to and eventually break through: a hard-cast finisher whose protection clause and evasive body close the game the turn it lands. This one rewrites the terms by hanging a mass-mind-control effect off the cast trigger. Because it fires the instant you announce the spell, the theft resolves while Emrakul is still on the stack: you take everything the target controls before the 12/12 has even entered, so the twelve mana buys an army defection alongside the flier. The leaves-the-battlefield sacrifice is the honest price. Those stolen creatures do not go home; the moment this body dies, your entire board goes with it, which turns the whole play into a one-turn wager that the game ends before Emrakul does. That downside is also the real reason cheating it into play is a trap: the steal is tied to casting, not to the enters trigger, so a reanimator or Sneak-Attack line gets the body without the army and inherits the sacrifice clause as pure liability.

The genuinely new lever is Madness for six colorless. Most twelve-cost Eldrazi are cast at full price or reanimated around it; here, any effect that forces or enables a discard becomes a payment plan, deploying a game-ending steal for half the mana at instant speed on an opponent's turn. Protection from spells makes it untargetable by instants and sorceries, so much of the usual reactive removal simply cannot reach it. The design line is legacy Eldrazi power routed through a colorless discard outlet rather than raw mana.