Mortuary + Ugin's Conjurant + Bolas's Citadel

Mortuary

Ugin's Conjurant

Bolas's Citadel

How it works

1. Cast Ugin's Conjurant either from your hand by paying 0 or from the top of your library by paying 0 life.
2. Ugin's Conjurant enters and dies as a state-based action due to having 0 toughness.
3. Mortuary triggers, putting Ugin's Conjurant from your graveyard onto the top of your library.
4. Repeat.

This ingenious loop revolves around casting Ugin's Conjurant for zero mana, allowing it to immediately hit the graveyard with zero toughness and trigger Mortuary to effortlessly cycle the creature right back to the top of your library. Meanwhile, Bolas's Citadel anchors the engine by letting you repeatedly cast Ugin's Conjurant straight from the top of your library—paying zero life for its mana value of zero, keeping your life total completely safe while generating infinite storm count, creature enters-the-battlefield, and death triggers.