Grimgrin, Corpse-Born + Rocksteady, Mutant Marauder

Grimgrin, Corpse-Born

Rocksteady, Mutant Marauder

How it works

1. Activate Grimgrin by sacrificing the persist creature.
2. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When the persist creature enters, Rocksteady triggers, putting a +1/+1 counter on that creature.
4. Resolve the Grimgrin ability.
5. Repeat