Nether Traitor + Pawn of Ulamog + Pitiless Plunderer + Altar of Dementia

Nether Traitor

Pawn of Ulamog

Pitiless Plunderer

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Nether Traitor.
2. When Nether Traitor dies, Pitiless Plunderer and Pawn of Ulamog trigger.
3. Resolve the Pitiless Plunderer trigger, creating a Treasure token.
4. Resolve the Pawn of Ulamog trigger, creating a 0/1 Eldrazi Spawn token.
5. Resolve the Altar of Dementia trigger, causing target player to mill one card.
6. Activate the Eldrazi Spawn token by sacrificing it, adding C.
7. When the Eldrazi Spawn dies, Pitiless Plunderer and Nether Traitor trigger.
8. Resolve the Pitiless Plunderer trigger, creating another Treasure token.
9. Activate a Treasure token by tapping and sacrificing it, adding .
10. Resolve Nether Traitor's trigger, paying to return it from your graveyard to the battlefield.
11. Repeat.