Nim Deathmantle + Su-Chi + Altar of Dementia

Nim Deathmantle

Su-Chi

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Su-Chi.
2. Su-Chi and Nim Deathmantle triggers.
3. Resolve the Su-Chi trigger, adding CCCC.
4. Resolve the Nim Deathmantle trigger, causing you to pay 4 to return Su-Chi from your graveyard to the battlefield, and then attach Nim Deathmantle to it.
5. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Su-Chi's power.
6. Repeat.

This engine spins into motion the moment you sacrifice Su-Chi to Altar of Dementia, utilizing the artifact creature's own dying breath to fund its immediate resurrection. When Su-Chi hits the graveyard, its death trigger generates the exact four mana needed to pay for the triggered ability of Nim Deathmantle, which pulls the construct right back to the battlefield and equips itself in the process. Meanwhile, Altar of Dementia turns each iteration of this infinite loop into a relentless wave of milling, grinding through an opponent's library until it's entirely gone.