Mortuary + Atog + Phyrexian Walker + Bolas's Citadel

Mortuary

Atog

Phyrexian Walker

Bolas's Citadel

How it works

1. Activate Atog 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 Atog ability.
4. Cast Phyrexian Walker from the top of your library by paying 0 life.
5. Repeat.

This delightful loop lets you churn through your deck by turning Atog into a bottomless pit for artifacts, though here we're using creatures instead! You simply sacrifice Phyrexian Walker to pump Atog, which triggers Mortuary to quietly place the Walker right back on top of your library. From there, Bolas's Citadel steps in to let you cast that same zero-mana artifact straight from the top of your library for zero life, priming the loop to start all over again.