Mortuary + Bolas's Citadel + Viscera Seer + Zulaport Cutthroat

Mortuary

Bolas's Citadel

Viscera Seer

Zulaport Cutthroat

How it works

1. Activate Viscera Seer by sacrificing it.
2. When Viscera Seer dies, Mortuary and Zulaport Cutthroat trigger.
3. Resolve the Mortuary trigger, putting Viscera Seer from your graveyard onto the top of your library.
4. Resolve the Zulaport Cutthroat trigger, causing you to gain 1 life and each opponent to lose 1 life.
5. Resolve the Viscera Seer ability.
6. Cast Viscera Seer from the top of your library by paying 1 life.
7. Repeat.

This elegant loop turns your library into a self-replenishing engine by leveraging Mortuary to constantly intercept creatures dying and redirect them right back to the top of your deck. From there, Bolas's Citadel allows you to bypass mana costs entirely, letting you replay that creature by paying life instead—a cost easily offset by Zulaport Cutthroat draining your opponents while padding your life total. Meanwhile, Viscera Seer provides both the cheap sacrifice outlet needed to fuel the loop and a way to manipulate the top of your library if things get cluttered, ensuring an endless storm of life loss and death triggers.