Cass, Hand of Vengeance, Altar of Dementia, and Ghostly Dancers

Prerequisites

• Cass, Hand of Vengeance on the battlefield
• Altar of Dementia on the battlefield
• Ghostly Dancers on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing another creature that has an Aura attached to it
2. When the creature dies, Cass triggers, returning an Aura that was attached to the creature from your graveyard to the battlefield attached to another creature you control
3. When the Aura enters the battlefield, Ghostly Dancers triggers, creating a creature token
4. Resolve the Altar of Dementia ability
5. Repeat

Results

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