Mortuary + Bolas's Citadel + Viscera Seer + Bastion of Remembrance

Mortuary

Bolas's Citadel

Viscera Seer

Bastion of Remembrance

How it works

1. Activate Viscera Seer by sacrificing it.
2. When Viscera Seer dies, Mortuary and Bastion of Remembrance trigger.
3. Resolve the Mortuary trigger, putting Viscera Seer from your graveyard onto the top of your library.
4. Resolve the Bastion of Remembrance 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 lets you recycle a single creature endlessly by turning your graveyard into a direct extension of your library. With Bolas's Citadel in play, you can cast Viscera Seer directly off the top of your library, trading mana costs for a tiny bit of life thanks to the Citadel's alternative casting condition. Every time you sacrifice Viscera Seer to its own ability, Mortuary immediately intercepts it on the way to the graveyard, placing the seer right back onto the top of your library for the Citadel to play again. Meanwhile, Bastion of Remembrance quietly watches the carnage, draining your opponents' life totals and padding your own life buffer with every single death and leaving-the-battlefield event to sustain the Citadel's life payments indefinitely.