Mortuary + Altar of Dementia + Bolas's Citadel + Kobolds of Kher Keep

Mortuary

Altar of Dementia

Bolas's Citadel

Kobolds of Kher Keep

How it works

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

This loop turns the zero-cost devotion of Kobolds of Kher Keep into an infinite engine by relying on Mortuary to intercept the creature as it dies and neatly recycle it straight back to the top of your library. From there, Bolas's Citadel grants you the ability to peer into your deck and continually recast those same free creatures from the top by paying zero life instead of mana. Each iteration feeds the sacrifice altar, allowing Altar of Dementia to mill your opponents out completely while generating an unbounded storm count and endless death triggers.