Cavalier of Night, Phantasmal Image, and Altar of Dementia

Prerequisites

• Cavalier of Night on the battlefield
• Phantasmal Image on the battlefield
• Altar of Dementia on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Phantasmal Image
2. When Phantasmal Image dies, its last ability from Cavalier of Night triggers, returning itself from your graveyard to the battlefield as a copy of Cavalier of Night
3. When Phantasmal Image enters the battlefield, its first triggered ability from Cavalier of Night triggers; choose not to sacrifice a creature
4. Resolve the Altar of Dementia ability from step 1
5. Repeat

Results

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