Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Yahenni, Undying Partisan + Nardole, Resourceful Cyborg

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

Yahenni, Undying Partisan

Nardole, Resourceful Cyborg

How it works

1. Activate Yahenni 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 Yahenni 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 Yahenni abilities from step 1 and 3.
6. Repeat.