Disa the Restless + Altar of Dementia + Arashin Sovereign + Arcane Adaptation

Disa the Restless

Altar of Dementia

Arashin Sovereign

Arcane Adaptation

How it works

1. Activate Altar of Dementia by sacrificing Arashin Sovereign.
2. When Arashin Sovereign dies, it triggers, putting itself from your graveyard onto the top of your library.
3. Resolve the Altar of Dementia ability, causing you to mill cards equal to Arashin Sovereign's power, which will cause you to mill Arashin Sovereign.
4. As Arashin Sovereign is a Lhurgoyf due to Arcane Adaptation, Disa's first ability triggers, returning Arashin Sovereign from your graveyard to the battlefield.
5. Repeat.

This elegant loop transforms Arashin Sovereign into an infinite-value engine by rewriting creature types with Arcane Adaptation so it counts as a Lhurgoyf. Once this type adjustment is in place, sacrificing the Sovereign to Altar of Dementia forces you to mill it back out of your library, triggering Disa the Restless to immediately cheat it back onto the battlefield from the graveyard. While the Sovereign's own death trigger normally tucks it onto the top or bottom of your library, milling it straight into the graveyard bypasses that restriction entirely and lets Disa's replacement effect do the heavy lifting. The result is an endless cycle of sacrifices and graveyard returns that mills your entire library while generating infinite enters-the-battlefield, leaves-the-battlefield, and death triggers.