Mortuary + Bolas's Citadel + Viscera Seer + Relic Vial

Mortuary

Bolas's Citadel

Viscera Seer

Relic Vial

How it works

1. Activate Viscera Seer by sacrificing it.
2. When Viscera Seer dies, Mortuary and Relic Vial trigger.
3. Resolve the Mortuary trigger, putting Viscera Seer from your graveyard onto the top of your library.
4. Resolve the Relic Vial 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.

By combining Bolas's Citadel with Mortuary, you create a self-sustaining loop where any creature that dies simply returns straight to the top of your library, ready to be cast again using life instead of mana. To make this engine run smoothly, Viscera Seer acts as the ultimate sacrifice outlet, letting you send your creatures away while simultaneously smoothing out your draws with its scry ability. Meanwhile, Relic Vial serves as your win condition and sustainability engine, draining your opponents' life totals and padding your own life total to fuel Bolas's Citadel's cost every time a creature meets its end.