Mortuary + Altar of Dementia + Bolas's Citadel + Crookshank Kobolds

Mortuary

Altar of Dementia

Bolas's Citadel

Crookshank Kobolds

How it works

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

This elegant loop relies on Crookshank Kobolds costing zero mana, allowing you to continually sacrifice it to Altar of Dementia to mill an opponent's entire library while triggering infinite deaths. Because Mortuary intercepts that sacrifice by immediately placing the Kobolds back onto the top of your library instead of letting them stay in the graveyard, Bolas's Citadel seamlessly takes over by letting you recast the creature straight from the top of your library for zero life. The Citadel's ability to see and play from the top of your library is what turns this zero-mana creature into an infinite engine, fueling endless sacrifices, enter-the-battlefield triggers, and storm count without ever running out of resources.