Chthonian Nightmare + Priest of Gix + Skittering Precursor + Yahenni, Undying Partisan

Chthonian Nightmare

Priest of Gix

Skittering Precursor

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing Priest of Gix.
2. When Priest of Gix dies, Skittering Precursor triggers, creating a 0/1 Eldrazi Spawn creature token.
3. Resolve the Yahenni ability.
4. Activate Chthonian Nightmare by paying EEE, sacrificing the Eldrazi Spawn and returning Chthonian Nightmare from the battlefield to your hand, returning Priest of Gix from your graveyard to the battlefield.
5. When Priest of Gix enters the battlefield, it triggers, adding .
6. Cast Chthonian Nightmare by paying 1.
7. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
8. Repeat.

This brilliant loop is fueled by Priest of Gix, whose entry mana and subsequent sacrifice fund Chthonian Nightmare's recurring energy cost and return it safely to your hand. As you sacrifice creatures to power the cycle, Skittering Precursor steps in to generate fodder through its Eldrazi Spawn tokens whenever a nontoken permanent hits the graveyard. Meanwhile, Yahenni, Undying Partisan provides the reliable sacrifice outlet you need to keep the engine turning, growing larger with every death trigger while threatening indestructible.