Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Spawning Pit + Nardole, Resourceful Cyborg

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

Spawning Pit

Nardole, Resourceful Cyborg

How it works

1. Activate Spawning Pit by sacrificing Nardole
2. When Nardole 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 Nardole
4. When Nardole 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.