Mortuary + Phyrexian Altar + Bolas's Citadel + Shield Sphere

Mortuary

Phyrexian Altar

Bolas's Citadel

Shield Sphere

How it works

1. Activate Phyrexian Altar by sacrificing Shield Sphere
2. When Shield Sphere dies, Mortuary triggers, putting Shield Sphere from your graveyard onto the top of your library.
3. Cast Shield Sphere from the top of your library by paying 0 life.
4. Repeat.

This clever loop turns the zero-mana artifact Shield Sphere into an endless engine of sacrifice and recursion. By sacrificing the Sphere to Phyrexian Altar, you generate any color of mana while triggering Mortuary, which neatly recycles the Sphere right back onto the top of your library. From there, Bolas's Citadel allows you to play the Shield Sphere over and over again from the top of your library for zero life, feeding the loop infinitely and generating boundless mana, storm count, and death triggers.