Hogaak, Arisen Necropolis + Caldaia Guardian + Altar of Dementia

Hogaak, Arisen Necropolis

Caldaia Guardian

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Hogaak.
2. When Hogaak dies, Caldaia Guardian triggers, creating two 1/1 Human Citizen creature tokens.
3. Resolve the Altar of Dementia ability, causing you to mill eight cards.
4. Cast Hogaak from your graveyard by tapping the two Human Citizen tokens and exiling five cards from your graveyard.
5. Repeat.
6. Once you have milled your library, you may continue the loop by milling opponents instead as allowed, and/or sacrifice the Human Citizens for extra mill.