Havengul Lich + Grimgrin, Corpse-Born + Cathodion + Utopia Vow

Havengul Lich

Grimgrin, Corpse-Born

Cathodion

Utopia Vow

How it works

1. Activate Grimgrin by sacrificing Cathodion, untapping Grimgrin and putting a +1/+1 counter on it.
2. When Cathodion dies, it triggers, adding mana equal to its casting cost.
3. Activate Grimgrin's ability from Utopia Vow by tapping Grimgrin, adding one mana.
4. Activate Havengul Lich by paying 1, allowing you to cast Cathodion from your graveyard this turn.
5. Cast Cathodion from your graveyard by paying its casting cost.
6. Repeat.

This intricate resurrection engine relies on the interplay between Grimgrin, Corpse-Born and the modular pieces in your graveyard and on the battlefield. By enchanting Cathodion with Utopia Vow, the automaton gains the ability to tap for mana, which helps offset the activation costs while its death trigger fuels the loop. Havengul Lich sits at the heart of the machinery, using its activated ability to let you recast Cathodion from the graveyard each time it is sacrificed to Grimgrin. As the loop cycles over and over, Grimgrin grows infinitely large on a mountain of endlessly returning metallic bones.