Cast Unearth by paying , targeting any applicable target.
Holding priority, cast Dualcaster Mage by paying 1.
When Dualcaster Mage enters, it triggers, targeting Unearth.
Holding priority, activate Goblin Bombardment by sacrificing Dualcaster Mage.
Resolve the Dualcaster Mage trigger, copying Unearth, with the copy targeting Dualcaster Mage.
Resolve the Unearth copy, returning Dualcaster Mage from your graveyard to the battlefield.
Repeat from step 3.
This cunning loop lets you turn a humble graveyard recursion spell into an endless execution machine. By casting Unearth to pull a creature back, you set up Dualcaster Mage to copy that very spell upon entry, creating an unbroken chain of recurring threats. Goblin Bombardment provides the crucial exit strategy, allowing you to sacrifice Dualcaster Mage to ping opponents and send it right back to the graveyard—priming the cycle to begin anew and incinerate the board with infinite damage.