Colossal Grave-Reaver + Altar of Dementia + Arashin Sovereign

Colossal Grave-Reaver

Altar of Dementia

Arashin Sovereign

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, ultimately milling Arashin Sovereign.
4. Colossal Grave-Reaver's second ability triggers, putting Arashin Sovereign from your graveyard onto the battlefield.
5. Repeat.