Desoshi the Maleficent

+1: Put a -1/-1 counter on target creature you control and a -1/-1 counter on target creature an opponent controls.
-1: Remove a -1/-1 counter from target creature you control: Put two -1/-1 counters on target creature an opponent controls. You lose 1 life.
-7: Destroy all creatures with -1/-1 counters on them. They can't be regenerated.