Cast Entering 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 Entering.
Holding priority, activate Goblin Bombardment by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Entering, with the copy targeting Dualcaster Mage
Resolve the Entering copy, returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
This clever loop turns a single spell into an endless engine of resurrection and destruction. You begin by casting the Entering half of Breaking // Entering, then interrupt it with Dualcaster Mage so its entry trigger targets the original spell. Before the copy resolves, Goblin Bombardment steps in to sacrifice Dualcaster Mage, sending it to the graveyard just in time for the newly created copy of Entering to drag it right back onto the battlefield. This creates an uninterrupted cycle that lets you repeatedly sacrifice and revive your mage, churning out infinite damage and death triggers to obliterate the table.