Rakdos, the Muscle + Priest of Gix + Haunted Crossroads + Hamza, Guardian of Arashin + Yahenni, Undying Partisan

Rakdos, the Muscle

Priest of Gix

Haunted Crossroads

Hamza, Guardian of Arashin

Yahenni, Undying Partisan

How it works

1. Activate Yahenni 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 Yahenni 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 looping sacrifice engine feeds on the mana and recursion enabled by its pieces to generate infinite black mana, death triggers, and storm count. You begin by sacrificing Priest of Gix to Yahenni, Undying Partisan, which triggers Rakdos, the Muscle to exile cards from the library while leveraging Haunted Crossroads to instantly recycle the Priest back to the top of your library. From there, you cast the Priest right back out of exile using the mana it produces upon entering the battlefield, a cost heavily discounted by Hamza, Guardian of Arashin.