Holding priority, cast Dualcaster Mage by paying its mana cost.
When Dualcaster Mage enters, it triggers, copying Scrollshift, with the copy targeting Dualcaster Mage.
Resolve the copy of Scrollshift, blinking Dualcaster Mage.
Repeat from step 3.
This elegant loop centers on the recursive synergy between Scrollshift and Dualcaster Mage, turning a simple blink spell into an unstoppable engine. By casting Scrollshift and flashing in Dualcaster Mage to copy it in response, you create a self-sustaining cycle where the copied spell perpetually exiles and returns the Mage to the battlefield. Each iteration triggers Dualcaster Mage anew to copy Scrollshift again, all while drawing you a card each time to easily dig through your entire deck.