Arc Ryleth, Evil Incarnate

Flying, Vigilance
Arc Ryleth gains a +1/+1 counters each time a creature dies on the battlefield.
If Arc Ryleth is destroyed or his toughness
becomes 0 or less, transform him, he will
still retain every +1/+1 counter he gained
while transformed.
Woe be upon the world for the evil you
have released!