Nim Deathmantle + Priest of Gix + Altar of Dementia + Pitiless Plunderer

Nim Deathmantle

Priest of Gix

Altar of Dementia

Pitiless Plunderer

How it works

1. Sacrifice Priest of Gix to Altar of Dementia, milling target opponent for 2.
2. Pitiless Plunderer and Nim Deathmantle triggers; resolve them in that order.
3. Pitiless Plunderer generates a Treasure token, crack it to float .
4. Resolve Nim Deathmantle's triggered ability, paying 4 to recur Priest of Gix to the battlefield (spending initial 3).
5. Priest of Gix's ETB trigger adds three .
6. Repeat from the top, milling target opponent infinitely.