Mikaeus, the Unhallowed + Bloodied Ghost + Evereth, Viceroy of Plunder

Mikaeus, the Unhallowed

Bloodied Ghost

Evereth, Viceroy of Plunder

How it works

1. Activate Evereth by sacrifiicing Bloodied Ghost.
2. When Bloodied Ghost dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it. When it enters, Bloodied Ghost will put a -1/-1 counter on itself, removing the +1/+1 counter.
3. Resolve the Evereth ability.
4. Repeat.
5. Activate Evereth by sacrificing Bloodied Ghost.
6. When Bloodied Ghost dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect.
7. Resolve the Evereth ability
8. Repeat.