Mortuary + Altar of Dementia + Bolas's Citadel + Fear of Lost Teeth

Mortuary

Altar of Dementia

Bolas's Citadel

Fear of Lost Teeth

How it works

1. Activate Altar of Dementia by sacrificing Fear of Lost Teeth.
2. When Fear of Lost Teeth dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Fear of Lost Teeth from your graveyard onto the top of your library.
4. Resolve the Fear of Lost Teeth trigger, causing you to gain 1 life and dealing 1 damage to any target.
5. Resolve the Altar of Dementia ability.
6. Cast Fear of Lost Teeth from the top of your library by paying 1 life due to Bolas's Citadel.
7. Repeat.

This elegant loop relies on Bolas's Citadel to let you bypass mana costs entirely, letting you cast spells directly from the top of your library by paying life instead. Altar of Dementia provides the necessary sacrifice outlet to mill your opponents while binning your creature. From there, Mortuary ensures that the sacrificed creature never stays in the graveyard, instantly sliding it right back to the top of your library to be recast. Finally, the demise of Fear of Lost Teeth triggers its own death ability to offset the life payment of the Citadel while pinging down the table, feeding the loop an endless cycle of self-sustaining value.