Altar of Dementia, Twilight Shepherd, and Thran Vigil

Prerequisites

• Altar of Dementia on the battlefield
• Twilight Shepherd on the battlefield
• Thran Vigil on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Twilight Shepherd
2. When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Thran Vigil triggers, putting a +1/+1 counter on Twilight Shepherd
4. Resolve the Altar of Dementia ability
5. Repeat

Results

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