Altar of Dementia + Dualcaster Mage + Extract from Darkness

Altar of Dementia

Dualcaster Mage

Extract from Darkness

How it works

1. Cast Extract from Darkness by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, targeting Extract from Darkness.
4. Holding priority, activate Altar of Dementia by sacrificing Dualcaster Mage.
5. Resolve the Dualcaster Mage trigger, copying Extract from Darkness
6. Resolve the Extract from Darkness copy, causing each player to mill two cards and returning Dualcaster Mage from your graveyard to the battlefield.
7. Repeat from step 3.

This clever loop turns a single reanimation spell into a self-sustaining engine by repeatedly leveraging Dualcaster Mage's entry trigger to copy Extract from Darkness. Each time the Mage brings itself back from the graveyard, Altar of Dementia provides a reliable way to send it right back there while simultaneously milling your opponents out.