Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, and Umbral Collar Zealot Combo

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, and Umbral Collar Zealot

Here's how the cards Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, and Umbral Collar Zealot results in Infinite LTB, Infinite ETB, Infinite sacrifice triggers, Infinite death triggers, and Infinite surveil 1

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

Umbral Collar Zealot

Prerequisites

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
Umbral Collar Zealot on the battlefield

Steps

Activate Umbral Collar Zealot by sacrificing the undying creature
When the creature dies, its undying ability triggers, returning the creature from your graveyard to the battlefield with a +1/+1 counter on it
Activate Umbral Collar Zealot by sacrificing the undying creature
When the creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
Resolve the Umbral Collar Zealot abilities from step 1 and 3
Repeat