Lord Skitter, Sewer King + Void Attendant + Pitiless Plunderer + Xenograft

Lord Skitter, Sewer King

Void Attendant

Pitiless Plunderer

Xenograft

How it works

1. Activate Void Attendant by paying 1 and putting a card an opponent owns from exile into their graveyard, creating a 1/1 Eldrazi Scion creature token.
2. When the Eldrazi Scion enters the battlefield as a Rat due to Xenograft, Lord Skitter's first ability triggers, exiling a card from an opponent's graveyard.
3. Activate the Eldrazi Scion by sacrificing it, adding C.
4. When the Eldrazi Scion dies, Pitiless Plunderer triggers, creating a Treasure artifact token.
5. Activate the Treasure by tapping and sacrificing it, adding .
6. Repeat.