Rakdos, the Muscle + Priest of Gix + Haunted Crossroads + Umbral Collar Zealot + Stone Calendar

Rakdos, the Muscle

Priest of Gix

Haunted Crossroads

Umbral Collar Zealot

Stone Calendar

How it works

1. Activate Umbral Collar Zealot by sacrificing Priest of Gix.
2. When Priest of Gix dies, Rakdos triggers.
3. Holding priority, activate Haunted Crossroads by paying , putting Priest of Gix from your graveyard onto the top of your library.
4. 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.
5. Resolve the Umbral Collar Zealot ability from step 1.
6. Cast Priest of Gix from exile by paying at most 2.
7. When Priest of Gix enters the battlefield, it triggers, adding .
8. Repeat.

This intricate loop centers around Rakdos, the Muscle, whose triggered ability exiles cards equal to a sacrificed creature's mana value for you to play, while simultaneously granting itself protection. To fuel this engine indefinitely, Priest of Gix enters the battlefield to provide a burst of mana, which is then discounted by Stone Calendar so you can easily recast it from exile. Umbral Collar Zealot provides the crucial sacrifice outlet that sends the Priest back to the graveyard, where Haunted Crossroads allows you to tuck it neatly back onto the top of your library just in time for Rakdos's exile effect to scoop it back up.