Koll, the Forgemaster, Skirk Prospector, and Umbral Mantle

Prerequisites

• Koll, the Forgemaster on the battlefield
• Skirk Prospector on the battlefield
• Umbral Mantle on the battlefield

Steps

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

Results

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