Lae'zel, Vlaakith's Champion + Pitiless Plunderer + Spawning Pit + Karn, Silver Golem

Lae'zel, Vlaakith's Champion

Pitiless Plunderer

Spawning Pit

Karn, Silver Golem

How it works

1. Activate Karn by paying 1, causing Spawning Pit to become a creature until end of turn.
2. Activate Spawning Pit's second ability by paying 1 and removing two charge counters from it, creating a 2/2 Spawn artifact creature token.
3. Activate Spawning Pit's first ability by sacrificing the Spawn.
4. The Spawn dies, triggering Pitiless Plunderer, creating a Treasure token.
5. Resolve the Spawning Pit ability, putting two charge counters on it.
6. Activate a Treasure by tapping and sacrificing it, adding 1.
7. Repeat from step 2.