Altar of Dementia, Dualcaster Mage, and Second Sunrise

Prerequisites

• Altar of Dementia on the battlefield
• Dualcaster Mage in hand
• Second Sunrise in hand
• available

Steps

1. Cast Second Sunrise by paying its mana cost Holding priority, cast Dualcaster Mage by paying its mana cost
2. When Dualcaster Mage enters, it triggers, targeting Second Sunrise
3. Holding priority, activate Altar of Dementia by sacrificing Dualcaster Mage
4. Resolve the Dualcaster Mage trigger, copying Second Sunrise Resolve the Second Sunrise copy, returning Dualcaster Mage from your graveyard to the battlefield
5. Repeat from step 3

Results

• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite self-mill
• Infinite magecraft triggers
• Infinite recursion of creature cards in your graveyard