Shepherd of the Cosmos, Altar of Dementia, and Ferocity of the Hunt

Prerequisites

• Shepherd of the Cosmos on the battlefield
• Altar of Dementia on the battlefield
• Ferocity of the Hunt on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Shepherd of the Cosmos
2. When Shepherd of the Cosmos dies, Ferocity of the Hunt triggers, returning Shepherd of the Cosmos from your graveyard to the battlefield
3. When Shepherd of the Cosmos enters the battlefield, it triggers, returning Ferocity of the Hunt from your graveyard to the battlefield attached to Shepherd of the Cosmos
4. Resolve the Altar of Dementia ability Repeat

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite mill
• Infinite self-mill