Qayin, the First-Damned

Qayin, the First-Damned enters the battlefield with X +1/+1 counters on it.
{3}, Remove a +1/+1 counter from Qayin: Put a 2/2 black Zombie creature token onto the battlefield.
When Qayin dies, if it had no +1/+1 counters on it, exile it. Otherwise, destroy all creatures.