Mortuary + Memnite + Bolas's Citadel + Yahenni, Undying Partisan

Mortuary

Memnite

Bolas's Citadel

Yahenni, Undying Partisan

How it works

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

This ingenious loop turns a zero-cost artifact into an engine of endless iteration, fueled entirely by life rather than mana thanks to Bolas's Citadel allowing you to cast spells straight from the top of your library. When you activate Yahenni, Undying Partisan by sacrificing Memnite, Mortuary catches the creature on its way to the graveyard and immediately places it right back on top of your library. Because Bolas's Citadel makes Memnite's mana value of zero cost you zero life to recast, you can repeat this sacrifice-and-draw cycle endlessly to rack up infinite death triggers, storm count, and creature leaves-the-battlefield and enters-the-battlefield events.