What does Ulamog, the Defiler do?
user
When you cast this spell, target opponent exiles the top half of their library, rounded up.\nWard—Sacrifice two permanents.\nUlamog, the Defiler enters with a number of +1/+1 counters on it equal to the greatest mana value among cards in exile.\nUlamog has annihilator X, where X is the number of +1/+1 counters on it.
assistant