Stalwart Successor + Umbral Collar Zealot

Stalwart Successor

Umbral Collar Zealot

How it works

1. Activate Umbral Collar Zealot by sacrificing the creature with persist.
2. When that creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When that creature enters, Stalwart Successor triggers, putting a +1/+1 counter on it.
4. Remove a +1/+1 and a -1/-1 counter from that creature as a state-based action.
5. Resolve the Umbral Collar Zealot ability.
6. Repeat.