Void Attendant + Pitiless Plunderer + Planar Void

Void Attendant

Pitiless Plunderer

Planar Void

How it works

1. Activate Void Attendant by paying 1 and putting a card an opponent owns from exile into their graveyard.
2. The card is instead put back into exile due to Planar Void.
3. Resolve the Void Attendant ability, creating a 1/1 Eldrazi Scion creature token.
4. Activate the Eldrazi Scion by sacrificing it, adding C.
5. The Eldrazi Scion dies, triggering Pitliess Plunderer, creating a Treasure token.
6. Activate the Treasure token by tapping and sacrificing it, adding .
7. Repeat.