Chthonian Nightmare + Priest of Gix + Cathodion

Chthonian Nightmare

Priest of Gix

Cathodion

How it works

1. Activate Chthonian Nightmare by paying EEE, sacrificing Cathodion and returning Chthonian Nightmare from the battlefield to your hand.
2. When Cathodion dies, it triggers, adding CCC.
3. Resolve the Chthonian Nightmare ability, returning Priest of Gix from your graveyard to the battlefield.
4. When Priest of Gix enters the battlefield, it triggers, adding .
5. Cast Chthonian Nightmare by paying 1.
6. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
7. Activate Chthonian Nightmare by paying EEE, sacrificing Priest of Gix and returning Chthonian Nightmare from the battlefield to your hand, returning Cathodion from your graveyard to the battlefield.
8. Cast Chthonian Nightmare by paying 1.
9. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
10. Repeat.

This clever loop relies on Chthonian Nightmare to constantly recycle creatures between the battlefield and your graveyard by fueling its activation costs with the energy it generates on re-entry. Meanwhile, Priest of Gix and Cathodion act as your economic engine; sacrificing Cathodion provides the colorless mana to help cover recasts, while Priest of Gix steps in to generate the black mana needed to replay the enchantment. By bouncing these two threats back and forth, you convert a single initial energy investment into an infinite surplus of mana, deaths, and entry triggers.