Nyxra, the Abyssal Phoenix

Flying, Deathtouch

Whenever a creature an opponent controls dies, if Nyxra, the Abyssal Phoenix is in your graveyard, you may exile that creature. If you do, return Nyxra to the battlefield with a +1/+1 counter on it.

Whenever Nyxra deals combat damage to a player, that player loses life equal to the number of creature cards in exile.