Woodfall Primus, Altar of Dementia, and Thran Vigil

Prerequisites

• Woodfall Primus on the battlefield
• Altar of Dementia on the battlefield
• Thran Vigil on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Woodfall Primus
2. When Woodfall Primus dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Thran Vigil and Woodfall Primus trigger
4. Resolve the Thran Vigil trigger, putting a +1/+1 counter on Woodfall Primus
5. Resolve the Woodfall Primus trigger, destroying target noncreature permanent
6. Resolve the Altar of Dementia ability Repeat

Results

• Destroy any number of noncreature permanents
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill
• Lock