Cloud Key + Umbral Collar Zealot Combos

2 known combos featuring both cards in Commander

Infinite LTB Infinite ETB Infinite storm count Infinite surveil Infinite sacrifice triggers

Combo 1 with Rakdos, the Muscle + Priest of Gix + Haunted Crossroads

Also requires:

Rakdos, the Muscle

Priest of Gix

Haunted Crossroads

Results: Infinite LTB · Infinite ETB · Infinite sacrifice triggers · Infinite death triggers · Infinite storm count · Infinite surveil · Exile your library with the ability to play the exiled cards until your next turn

Steps

Activate Umbral Collar Zealot by sacrificing Priest of Gix.
When Priest of Gix dies, Rakdos triggers.
Holding priority, activate Haunted Crossroads by paying {B}, putting Priest of Gix from your graveyard onto the top of your library.
Resolve the Rakdos trigger, causing you to exile the top three cards of your library with the ability to play them until your next end step.
Resolve the Umbral Collar Zealot ability from step 1.
Cast Priest of Gix from exile by paying {2}
When Priest of Gix enters the battlefield, it triggers, adding {B}{B}{B}.
Repeat.

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