Cast Fake Your Own Death by paying 1, targeting any creature.
Holding priority, cast Dualcaster Mage by paying 1.
When Dualcaster Mage enters the battlefield, it triggers, copying Fake Your Own Death, targeting Dualcaster Mage.
Resolve the copy of Fake Your Own Death.
Holding priority, activate Yahenni, Undying Partisan by sacrificing Dualcaster Mage.
When Dualcaster Mage dies, it triggers, returning itself from your graveyard to the battlefield and creating a Treasure token.
Repeat from step 3.
This clever loop relies on Yahenni, Undying Partisan standing ready to continuously sacrifice Dualcaster Mage whenever the wizard blinks back into play. With Fake Your Own Death cast to grant its persistent resurrection and Treasure-generating effect, every cycle nets you a fresh artifact token while infinitely looping Dualcaster Mage's entry trigger to copy the spell anew.