Mikaeus, the Unhallowed + Bartolomé del Presidio + Gravelgill Axeshark

Mikaeus, the Unhallowed

Bartolomé del Presidio

Gravelgill Axeshark

How it works

1. Activate Bartolomé del Presidio by sacrificing Gravelgill Axeshark.
2. When Gravelgill Axeshark dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Bartolomé del Presidio ability.
4. Activate Bartolomé del Presidio by sacrificing Gravelgill Axeshark.
5. When Gravelgill Axeshark dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Bartolomé del Presidio ability.
7. Repeat.