All 16 Combos with Propeller Pioneer

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Umbral Collar Zealot + Propeller Pioneer

Other: Infinite LTB, Infinite ETB, Infinite sacrifice triggers, Infinite death triggers, Infinite surveil

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

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