Altar of Dementia + Dualcaster Mage + Living Death

Altar of Dementia

Dualcaster Mage

Living Death

How it works

1. Cast Living Death by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, targeting Living Death.
4. Holding priority, activate Altar of Dementia by sacrificing Dualcaster Mage.
5. Resolve the Dualcaster Mage trigger, copying Living Death
6. Resolve the Living Death copy, causing each player to exile all creature cards from their graveyard, sacrifice all creatures they control, and returning all cards exiled this way to the battlefield under their owner's control.
7. Repeat from step 3.