Altar of Dementia, Undying Malice, and Dualcaster Mage

Prerequisites

• Altar of Dementia on the battlefield
• Undying Malice in hand
• Dualcaster Mage in hand
• available

Steps

1. Cast Undying Malice by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost
3. When Dualcaster Mage enters, it triggers, copying Undying Malice, with the copy targeting Dualcaster Mage
4. Resolve the copy of Undying Malice
5. Holding priority, activate Altar of Dementia by sacrificing Dualcaster Mage
6. When Dualcaster Mage dies, it triggers, returning it from your graveyard to the battlefield
7. Repeat from step 3
8. Resolve all Altar of Dementia abilities from step 5

Results

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