Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Spawning Pit + Howlgeist

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

Spawning Pit

Howlgeist

How it works

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