Chthonian Nightmare + Greedy Freebooter + Shambling Ghast + Thunderscape Familiar

Chthonian Nightmare

Greedy Freebooter

Shambling Ghast

Thunderscape Familiar

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 clever recursive loop turns Chthonian Nightmare into a perpetual motion machine by continuously recycling cheap threats between the battlefield and the graveyard. Thanks to Thunderscape Familiar passively discounting your black spells, recasting the enchantment only costs a single black mana, which is conveniently generated each cycle by sacrificing Greedy Freebooter and Shambling Ghast for their respective Treasure tokens. As these two sacrifice fodder creatures trade places with each other over and over, the net energy cost drops to just one per iteration—easily sustained by the enchantment's own entry trigger—while spinning off an endless stream of death, sacrifice, and scry triggers.