Activate Emiel the Blessed by paying 3, blinking Skullport Merchant.
When Skullport Merchant enters the battlefield, it triggers twice, and Preston trigger twice if it has power 2 or less, or once otherwise.
Resolve both Skullport Merchant triggers, creating two Treasure artifact tokens.
Resolve the first Preston trigger, creating a token copy of Skullport Merchant that is a 0/1 Illusion.
When the Skullport Merchant token enters the battlefield, it triggers twice, creating two Treasure tokens.
Repeat from step 4 for the remaining Preston trigger, if applicable.
Activate three Treasures by tapping and sacrificing them, adding 3.
Repeat.
This clever loop turns Emiel the Blessed into a self-sustaining engine by repeatedly blinking Skullport Merchant. As the Merchant enters and leaves the battlefield, Delney, Streetwise Lookout doubles its entry trigger to generate a surplus of Treasure tokens, which easily fund Emiel's activation cost while providing fodder for Skullport Merchant's own card-drawing ability if needed. Meanwhile, Preston, the Vanisher watches these uncast creatures arrive and responds by creating an army of 0/1 Illusion token copies that endlessly perpetuate the loop and flood the board.