Colossal Grave-Reaver, Altar of Dementia, and Mortuary

Prerequisites

• Colossal Grave-Reaver on the battlefield
• Altar of Dementia on the battlefield
• Mortuary on the battlefield
• undefined

Steps

1. Activate Altar of Dementia by sacrificing another nontoken creature with power 1 or greater
2. When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library
3. Resolve the Altar of Dementia ability, causing you to mill cards equal to the creature's power, ultimately milling the creature
4. Colossal Grave-Reaver's second ability triggers, putting the creature from your graveyard onto the battlefield
5. Repeat

Results

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