Mortuary + Bolas's Citadel + Dross Harvester + Viscera Seer

Mortuary

Bolas's Citadel

Dross Harvester

Viscera Seer

How it works

1. Activate Viscera Seer by sacrificing it.
2. When Viscera Seer dies, Mortuary and Dross Harvester trigger.
3. Resolve the Mortuary trigger, putting Viscera Seer from your graveyard onto the top of your library.
4. Resolve the Dross Harvester trigger, causing you to gain 2 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 churn through your deck indefinitely by turning Viscera Seer into a self-recycling engine. While Viscera Seer provides the sacrifice outlet, Mortuary ensures the sacrificed creature never truly stays dead by slipping it straight back to the top of your library. From there, Bolas's Citadel allows you to recast that creature directly off the library using life instead of mana, while Dross Harvester steps in to pad your life total whenever a creature dies to completely offset the casting cost.