Koll, the Forgemaster, Blood Pet, and Umbral Mantle

Prerequisites

• Koll, the Forgemaster on the battlefield
• Blood Pet on the battlefield
• Umbral Mantle on the battlefield

Steps

1. Activate Umbral Mantle's equip ability by paying , attaching it to Blood Pet
2. Activate Blood Pet by sacrificing it, adding
3. When Blood Pet dies, Koll triggers, returning Blood Pet from your graveyard to your hand
4. Cast Blood Pet by paying
5. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count