Cast Persist by paying its mana cost, targeting any applicable target.
Holding priority, cast Dualcaster Mage by paying its mana cost.
When Dualcaster Mage enters, it triggers, targeting Persist.
Holding priority, activate Viscera Seer by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Persist, with the copy targeting Dualcaster Mage
Resolve the Persist copy, returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
This clever loop turns a simple recursion spell into an endless engine by using Dualcaster Mage's entry trigger to continuously copy Persist from the stack, bringing the Mage right back from the graveyard every time it dies. While Persist normally leaves a -1/-1 counter behind, it doesn't matter here because the Mage enters fresh from the graveyard each cycle, allowing Viscera Seer to safely sacrifice it over and over again. As the Mage repeatedly enters and departs, Viscera Seer lets you comb infinitely through your library with endless scry triggers, filtering your draws while churning out a boundless stream of sacrifices.