Holding priority, cast Dualcaster Mage by paying its mana cost.
When Dualcaster Mage enters, it triggers, targeting Victimize.
Holding priority, activate Viscera Seer by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Victimize
Resolve the Victimize copy, sacrificing a creature and returning Dualcaster Mage and another creature from your graveyard to the battlefield.
Repeat from step 3.
This clever loop relies on Victimize to pull creatures from the graveyard, utilizing the additional sacrifice cost to fuel Viscera Seer and ensure your pieces keep heading back to the bin. When you cast Victimize and float Dualcaster Mage into the mix, the Mage's entry trigger copies the original spell to keep the cycle going. Meanwhile, Viscera Seer offers a handy sacrifice outlet to trigger the loop on command while digging through your deck with infinite scry 1s.