Magryn, the Vengeant

+1: Create two 1/1 black bat creature tokens with flying and deathtouch.
-1: Deal 1 damage to target creature and put a bite counter on it. When that creature dies, return it to the battlefield under your control.
-7: Destroy all creatures. Exile Magryn. Deal 1 damage to each player for each creature destroyed. If player loses the game this turn, return Magryn