Umbral Collar Zealot + Thran Vigil + Safehold Elite

Umbral Collar Zealot

Thran Vigil

Safehold Elite

How it works

1. Activate Umbral Collar Zealot by sacrificing Safehold Elite.
2. When Safehold Elite dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Thran Vigil triggers, putting a +1/+1 counter on Safehold Elite.
4. Resolve the Umbral Collar Zealot ability.
5. Repeat.