Havengul Lich + Shambling Ghast + Umbral Collar Zealot + Delney, Streetwise Lookout

Havengul Lich

Shambling Ghast

Umbral Collar Zealot

Delney, Streetwise Lookout

How it works

1. Activate Havengul Lich by paying 1, allowing you to cast Shambling Ghast card from your graveyard this turn.
2. Cast Shambling Ghast from your graveyard by paying .
3. Activate Umbral Collar Zealot by sacrificing Shambling Ghast.
4. When Shambling Ghast dies, it triggers twice, creating two Treasure tokens.
5. Resolve the Umbral Collar Zealot ability.
6. Activate the Treasures by tapping and sacrificing them, adding 1
7. Repeat.

This loop transforms your graveyard into a self-sustaining engine by taking advantage of Havengul Lich's ability to repeatedly cast a fallen creature from your graveyard for a single mana. Shambling Ghast serves as the perfect fuel here, because when you sacrifice it to Umbral Collar Zealot's activation cost, its death trigger kicks off. Thanks to Delney, Streetwise Lookout doubling that death trigger because of the Ghast's low power, you get back two Treasure tokens for every one you sacrifice to pay the casting cost. The result is an infinite loop of sacrifices and mana generation, which Umbral Collar Zealot simultaneously turns into infinite surveils to completely sculpt your library.