Cass, Hand of Vengeance, Griffin Guide, and Spawning Pit

Prerequisites

• Cass, Hand of Vengeance on the battlefield
• Griffin Guide on the battlefield
• Spawning Pit on the battlefield

Steps

1. Activate Spawning Pit by sacrificing the creature with Griffin Guide attached
2. When the creature dies, Cass and Griffin Guide trigger
3. Resolve the Griffin Guide trigger, creating a 2/2 Griffin creature token
4. Resolve the Cass trigger, returning Griffin Guide from your graveyard to the battlefield attached to another creature you control
5. Resolve the Spawning Pit ability Repeat

Results

• Infinite charge counters on a permanent
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers