Koh, the Face Stealer

Whenever Koh, the Face Stealer enters the
battlefield exile target creature. Koh, the
Face Stealer becomes a copy of the creature.
Whenever Koh blocks or becomes blocked
by a creature, you may exile that creature,
if you do Koh, the Face Stealer becomes a
copy of that creature. Then return all other
creatures exiled with Koh, The Face Stealer
to the battlefield tapped.