Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Propeller Pioneer + Yahenni, Undying Partisan

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

Propeller Pioneer

Yahenni, Undying Partisan

How it works

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