Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Yahenni, Undying Partisan + Gleeful Arsonist

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Yahenni, Undying Partisan

Gleeful Arsonist

How it works

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