Altar of Dementia, Thran Vigil, and Persistent Constrictor

Prerequisites

• Altar of Dementia on the battlefield
• Thran Vigil on the battlefield
• Persistent Constrictor on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Persistent Constrictor
2. When Persistent Constrictor 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 Persistent Constrictor
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