Eventide

Aerie Ouphes

Sacrifice Aerie Ouphes: Aerie Ouphes deals damage equal to its power to target creature with flying.
Persist (When this creature is put into a graveyard from play, if it had no -1/-1 counters on it, return it to play under its owner's control with a -1/-1 counter on it.)

Sacrifice Aerie Ouphes: It deals damage equal to its power to target creature with flying.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)