Rakdos, the Muscle + Shambling Ghast + Haunted Crossroads + Prosper, Tome-Bound + Yahenni, Undying Partisan

Rakdos, the Muscle

Shambling Ghast

Haunted Crossroads

Prosper, Tome-Bound

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing Shambling Ghast.
2. When Shambling Ghast dies, it and Rakdos trigger.
3. Resolve the Shambling Ghast trigger, creating a Treasure token.
4. Activate the Treasure by tapping and sacrificing it, adding .
5. Holding priority, activate Haunted Crossroads by paying , putting Shambling Ghast from your graveyard onto the top of your library.
6. Resolve the Rakdos trigger, exiling Shambling Ghast from the top of your library with the ability to cast it until your next turn.
7. Resolve the Yahenni ability.
8. Cast Shambling Ghast from exile by paying 1.
9. Prosper triggers, creating a Treasure token.
10. Activate the Treasure by tapping and sacrificing it, adding 1.
11. Repeat.

This clever loop uses Yahenni, Undying Partisan as your dedicated sacrifice outlet, feeding it Shambling Ghast repeatedly to trigger endless deaths while growing Yahenni's size. Each time the Ghast hits the graveyard, you can use the mana from its created Treasure—or a bonus Treasure generated by Prosper, Tome-Bound's Pact Boon whenever you cast a card from exile—to fund Haunted Crossroads, tucking Shambling Ghast right back onto the top of your library. From there, Rakdos, the Muscle exiles the Ghast as it gets sacrificed, allowing you to seamlessly recast it from exile and keep the engine turning indefinitely.