Mortuary + Ashnod's Altar + Bolas's Citadel + Haywire Mite

Mortuary

Ashnod's Altar

Bolas's Citadel

Haywire Mite

How it works

1. Activate Ashnod's Altar by sacrificing Haywire Mite.
2. When Haywire Mite dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Haywire Mite from your graveyard onto the top of your library.
4. Resolve the Haywire Mite trigger, causing you to gain 2 life
5. Cast Haywire Mite from the top of your library by paying 1 life due to Bolas's Citadel.
6. Repeat.

This elegant engine turns a humble automaton into a self-sustaining loop by leveraging the life-substitution effect of Bolas's Citadel to cast spells straight from your library without spending mana. Whenever Ashnod's Altar sacrifices Haywire Mite for colorless mana, Mortuary catches the insect in your graveyard and places it right back on top of your library where the Citadel can see it again. Meanwhile, Haywire Mite's own death trigger offsets the life payment required to recast it, netting you a positive life total alongside infinite sacrifices, triggers, and colorless mana.