Mortuary + Zulaport Cutthroat + Bolas's Citadel + Carrion Feeder

Mortuary

Zulaport Cutthroat

Bolas's Citadel

Carrion Feeder

How it works

1. Activate Carrion Feeder by sacrificing it.
2. When Carrion Feeder dies, Mortuary and Zulaport Cutthroat trigger.
3. Resolve the Mortuary trigger, putting Carrion Feeder 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 Carrion Feeder ability.
6. Cast Carrion Feeder from the top of your library by paying 1 life.
7. Repeat.

This loop transforms your library into a self-sustaining engine by letting **Bolas's Citadel** bypass conventional mana costs entirely, replacing them with life payments to repeatedly cast **Carrion Feeder** from the top of your deck. Whenever **Carrion Feeder** is sacrificed to its own ability, **Mortuary** immediately catches it on its way to the graveyard and places it right back on top of your library for the **Bolas's Citadel** to play once more. Meanwhile, **Zulaport Cutthroat** sits on the battlefield watching the endless cycle of deaths and resurrections, effortlessly draining your opponents' life totals while easily offsetting the life you pay to recast your sacrifice outlet.