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

Prerequisites

• Lae'zel, Vlaakith's Champion on the battlefield
• Pitiless Plunderer on the battlefield
• Spawning Pit on the battlefield
• Karn, Silver Golem on the battlefield
• Spawning Pit has at least two charge counters
• available

Steps

1. Activate Karn by paying , causing Spawning Pit to become a creature until end of turn
2. Activate Spawning Pit's second ability by paying 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
7. Repeat from step 2

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers