Mortuary + Phyrexian Walker + Bolas's Citadel + Carrion Feeder

Mortuary

Phyrexian Walker

Bolas's Citadel

Carrion Feeder

How it works

1. Activate Carrion Feeder by sacrificing Phyrexian Walker
2. When Phyrexian Walker dies, Mortuary triggers, putting Phyrexian Walker from your graveyard onto the top of your library.
3. Resolve the Carrion Feeder ability.
4. Cast Phyrexian Walker from the top of your library by paying 0 life.
5. Repeat.

This clever engine centers around Bolas's Citadel, which lets you cast spells straight from the top of your library by paying life instead of mana. With Mortuary stationed on the battlefield, any creature sent to your graveyard immediately slips back onto the top of your library, perfectly teeing it up for the Citadel's top-deck casting permission. By feeding Phyrexian Walker to Carrion Feeder, you trigger the Walker's death and subsequent return to the library for zero life. This creates an endless loop of sacrifices that pumps up Carrion Feeder while generating infinite storm count, death triggers, and enter-the-battlefield effects.