Holding priority, cast Dualcaster Mage by paying its mana cost.
When Dualcaster Mage enters, it triggers, copying Presumed Dead, with the copy targeting Dualcaster Mage.
Resolve the copy of Presumed Dead.
Holding priority, activate Umbral Collar Zealot by sacrificing Dualcaster Mage.
When Dualcaster Mage dies, it triggers, returning it from your graveyard to the battlefield.
Repeat from step 3.
Resolve all Umbral Collar Zealot abilities from step 5.
This elegant loop turns **Presumed Dead** and **Dualcaster Mage** into a self-sustaining resurrection engine, continuously leveraging the Mage's entry trigger to target itself with a fresh copy of the spell. As **Dualcaster Mage** repeatedly dies and returns to the battlefield, **Umbral Collar Zealot** acts as the crucial sacrifice outlet that enables this cycle while weaponizing the constant deaths to surveil your entire library.