Emiel the Blessed | Preston, the Vanisher | Delney, Streetwise Lookout (and one other card)

Cards

Activate
Emiel the Blessed by paying ({3} magic symbol) , blinking
Burdened Aerialist.
When
Burdened Aerialist enters the battlefield, it triggers once, and
Preston triggers twice.
Resolve the
Burdened Aerialist trigger, creating a Treasure token.
Resolve the first
Preston trigger, creating a token copy of
Burdened Aerialist that is a 0/1 Illusion.
When the
Burdened Aerialist token enters the battlefield, it triggers, creating a Treasure token.
Repeat from step 4 for the remaining
Preston trigger.
Activate three Treasures by tapping and sacrificing them, adding ({3} magic symbol) .
Repeat.

This combo has been estimated to be Exhibition (Bracket 1+).