Chthonian Nightmare + Greedy Freebooter + Shambling Ghast + Mana Matrix

Chthonian Nightmare

Greedy Freebooter

Shambling Ghast

Mana Matrix

How it works

1. Cast Chthonian Nightmare by paying .
2. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
3. Activate Chthonian Nightmare by paying E, sacrificing Greedy Freebooter and returning Chthonian Nightmare from the battlefield to your hand.
4. When Greedy Freebooter dies, it triggers, causing you to scry 1 and create a Treasure token.
5. Resolve the Chthonian Nightmare ability, returning Shambling Ghast from your graveyard to the battlefield.
6. Activate the Treasure by tapping and sacrificing it, adding .
7. Cast Chthonian Nightmare by paying .
8. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
9. Activate Chthonian Nightmare by paying E, sacrificing Shambling Ghast and returning Chthonian Nightmare from the battlefield to your hand.
10. When Shambling Ghast dies, it triggers, creating a Treasure token.
11. Resolve the Chthonian Nightmare ability, returning Greedy Freebooter from your graveyard to the battlefield.
12. Activate the Treasure by tapping and sacrificing it, adding .
13. Repeat.

This elegant loop relies on Chthonian Nightmare cycling back and forth between the battlefield and your hand while continually resurrecting your sacrifice fodder. Greedy Freebooter and Shambling Ghast serve as interchangeable engines when they hit the graveyard, each replacing themselves with a Treasure token upon death to fund the next casting. Meanwhile, Mana Matrix eases the burden on your mana pool by reducing the enchantment's cost, allowing you to seamlessly recast it using the mana generated by the Treasures.