Ulamog, the Defiler

Mana Cost: {10}
Total Cost: 10
Type: Legendary Creature — Eldrazi
Description: When you cast this spell, target opponent exiles the top half of their library, rounded up.
Ward—Sacrifice two permanents.
Ulamog enters with a number of +1/+1 counters on it equal to the greatest mana value among cards in exile.
Ulamog has annihilator X, where X is the number of +1/+1 counters on it.
Power: 7
Toughness: 7