Calamity Ganon

When you cast this spell, target opponent exiles half
their library, rounded up.

Ward - Sacrifice two permanents.

Calamity Ganon enters the battlefield with a
number of +1/+1 counters on it equal to the greatest
mana value among cards in exile.

Calamity Ganon has annihilator X, where X is the
number of +1/+1 counters on it.