Activate Emiel the Blessed by paying 3, blinking Charming Scoundrel.
When Charming Scoundrel enters the battlefield, it triggers twice, and Preston triggers twice if it has power 2 or less, or once otherwise.
Resolve the Charming Scoundrel triggers, creating two Treasure tokens.
Resolve the first Preston trigger, creating a token copy of Charming Scoundrel that is a 0/1 Illusion.
When the Charming Scoundrel 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 delightful loop relies on Emiel the Blessed acting as an infinite blink engine, repeatedly exiling and returning Charming Scoundrel to the battlefield to squeeze maximum value out of its entry triggers. Delney, Streetwise Lookout plays a crucial supporting role by boosting Charming Scoundrel's entry triggers—and Preston, the Vanisher's triggers, assuming the copied creature's power is 2 or less—so that blinking generates an excess of resources. Preston, the Vanisher capitalizes on these uncast entries by spitting out 0/1 illusion copies of Charming Scoundrel, which immediately trigger more enter-the-battlefield effects of their own. Because Charming Scoundrel can choose to create Treasure tokens upon entry, the mana generated by sacrificing those tokens more than pays for Emiel the Blessed's activation cost, locking in an endless cycle of perpetual motion.