Mikaeus, the Unhallowed + Umbral Collar Zealot + Restless Apparition

Mikaeus, the Unhallowed

Umbral Collar Zealot

Restless Apparition

How it works

1. Activate Umbral Collar Zealot by sacrificing Restless Apparition.
2. When Restless Apparition dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Umbral Collar Zealot ability.
4. Activate Umbral Collar Zealot by sacrificing Restless Apparition.
5. When Restless Apparition dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Umbral Collar Zealot ability.
7. Repeat.