Bard!Dustin and Mage!El as Flynn Rider and Rapunzel.
Dustin gets separated from the Party and is on the run from local militia for inciting a riot (the feudal lord was totally corrupt), when he stumbles upon a strange tower where he meets a girl who doesn't know her real name or even when her birthday is. Dustin just wants to reunite with his friends again but is forced to take this strange girl to see the "floating lights" because she stole his research papers and he really needs those back.
Dustin ends up showing her the world, explaining it to her in terms she can understand and never tiring of her many questions because he's always respected curiosity. They end up going to Eddie's Place which is this really dingy tavern, and at first, El is a little freaked out by all these strange, gruff-looking people, but they actually all turn out to be complete softies, especially Eddie who gives Dustin a lot of nudging and eyebrow waggles when El isn't looking. Unfortunately, the guard catches up with Dustin, and they have to leave. While they're on the run, Dustin and El get trapped in an underwater cave, and Dustin's freaking out because he thinks they're going to die, but then El just busts them out, and now Dustin is freaking out because apparently this strange girl he's been hanging out with for the past few days is the most powerful mage he's ever seen.
They end up in the city where Dustin tells El about the lost princess. He tells her that one of his best friends, Will, is the prince and the lost princes was his twin and how the Party spent many years looking for her before they finally gave up.
Dustin takes El to see the floating lights, but just before they kiss, Dustin sees Suzie, an ex of his and his old research partner. He tells El that he'll be right back and tells Suzie that she can have the papers as long as she leaves him alone. But Suzie tells him she's struck a deal with another scientist, Dr. Brenner, and he told her about his greatest creation, the mage. Suzie now wants to capture El so that she can do experiments on her. She knocks Dustin out and hands him over to the local militia, and El goes back with Dr. Brenner.
Dustin is rescued from execution when the Party finally find him. Will, as prince, is able to pardon Dustin, and Dustin tells them all about his experience with El. The three of them help Dustin find the tower again, but it's guarded by demogorgons. While the rest of the party fight them, Dustin sneaks into the tower. He confronts Dr. Brenner who has El convinced that she's a monster and doesn't belong in society. But just then, something clicks for Dustin and he realizes that El is the lost princess. He tells her and begs her to come back with him and live a free life. Dr. Brenner then tries to stab him, but El stops him with her powers and kills Dr. Brenner.
Dustin and El confess their feelings for each other and have a sweet, romantic moment together. Then, the whole party joins them and Will and El have an emotional reunion. They all take El back to the city where she is able to reunite with Hopper, Joyce, and Jonathan as well. And they all live happily ever after.
Also, El has a pet bunny named Bun-Bun. Not really plot relevant, but I thought you should know.