Mikaeus, the Unhallowed + Furystoke Giant + Yahenni, Undying Partisan

Mikaeus, the Unhallowed

Furystoke Giant

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing Furystoke Giant.
2. When Furystoke Giant 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 Furystoke Giant.
5. When Furystoke Giant 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.