Mikaeus, the Unhallowed + Wingrattle Scarecrow + Yahenni, Undying Partisan

Mikaeus, the Unhallowed

Wingrattle Scarecrow

Yahenni, Undying Partisan

How it works

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