Gerrard, Weatherlight Hero + Cauldron of Souls + Extruder + Umbral Collar Zealot

Gerrard, Weatherlight Hero

Cauldron of Souls

Extruder

Umbral Collar Zealot

How it works

1. Activate Cauldron of Souls by tapping it, giving Gerrard persist until end of turn.
2. Activate Extruder by sacrificing Cauldron of Souls, putting a +1/+1 counter on Gerrard.
3. Activate Umbral Collar Zealot by sacrificing Gerrard.
4. When Gerrard dies, it and its persist ability trigger.
5. Resolve the Gerrard persist trigger, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
6. Resolve the second Gerrard trigger, failing to exile it as it has left your graveyard, and returning Cauldron of Souls from your graveyard to the battlefield.
7. Resolve the Umbral Collar Zealot ability from step 3, putting a +1/+1 counter on it.
8. Repeat.

This intricate loop revolves around recycling your board state using Gerrard, Weatherlight Hero as both the engine and the payoff. By granting Gerrard persist via Cauldron of Souls, you can sacrifice it to Umbral Collar Zealot along with Cauldron of Souls itself (fed to Extruder beforehand). When Gerrard dies, both its natural resurrection trigger and its new persist ability fire simultaneously; the persist brings Gerrard back with a -1/-1 counter, while the death trigger brings back Cauldron of Souls. Extruder's ability to distribute +1/+1 counters then instantly neutralizes the -1/-1 counter on Gerrard, resetting the loop so you can repeat the process indefinitely for infinite sacrifices, triggers, and surveils.