Babble

Presenting an elaborate crossover featuring characters from Pixar's Up, Coco, Inside Out, and Loop, Dreamworks' Trolls, The Bad Guys, and Rise of the Guardians, and Disneys' Gravity Falls. Also contains original characters who'll be announced as they enter the story.
Teenage Riley and Miguel go to work at a mysterious clinic, only to find the patients are Supers, the doctors are Bergens, and a series of interdimensional rifts are bringing four worlds together.
Questions and suggestions are welcome. Some chapters might be edited as the story progresses. Rough drafts of individual chapter can be read on Tumblr with the hashtag #babble au.
(Just so you know; this takes place after the cannon events in Rise of the Guardians, before the cannon events in the Trolls movies, after the Pixar cannon events and midway through Gravity Falls cannon events.)