Flying, Afflict 6

Whenever a creature dies, put a -1/-1 counter on target creature you don't control.

Whenever a creature you control dies, put a +1/+1 counter on Rergat. If you do, search your library or graveyard for a creature with converted mana cost less than or equal to the number of counters on Rergat. Put that card onto the battlefield. If this creature entered the battlefield from your library, shuffle.