Spawning Pit + Master Biomancer

Spawning Pit

Master Biomancer

How it works

1. Activate Spawning Pit 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 and at least one +1/+1 counter on it due to Master Biomancer.
3. Remove a -1/-1 counter and a +1/+1 counter from that creature as a state-based action.
4. Resolve the Spawning Pit ability.
5. Repeat