Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Spawning Pit + Ambitious Aetherborn

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

Spawning Pit

Ambitious Aetherborn

How it works

1. Activate Spawning Pit by sacrificing Ambitious Aetherborn.
2. When Ambitious Aetherborn dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Ambitious Aetherborn enters, its fabricate ability triggers, putting a +1/+1 counter on it.
4. Resolve the Spawning Pit ability.
5. Repeat.