Altar of Dementia + Dualcaster Mage + Presumed Dead

Altar of Dementia

Dualcaster Mage

Presumed Dead

How it works

1. Cast Presumed Dead by paying its mana cost.
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, copying Presumed Dead, with the copy targeting Dualcaster Mage.
4. Resolve the copy of Presumed Dead.
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.

This ingenious loop hinges on Dualcaster Mage copying a spell that continually defies death, turning a single pair of spells into an endless cycle of self-preservation. When you cast Presumed Dead and flash in Dualcaster Mage, the Mage's enter-the-battlefield trigger targets itself with a copied resurrection effect, granting it a delayed trigger to return whenever it perishes. Before that copy resolves, you can feed the Mage to Altar of Dementia to mill an opponent, triggering its new dying condition to bring it right back to the battlefield. Because Dualcaster Mage re-enters and immediately copies Presumed Dead once more, the entire sequence resets indefinitely, letting you grind through your opponent's entire library one sacrifice at a time.