Divine Intervention

The day Adrien Agreste planned to propose to his longterm girlfriend, Marinette, he gets sucked into an alternate universe where the magic of the kwamis doesn't quite work the same. As he tries to get used to this new world, find his way back home and understand why he was brought to this new place, Marinette does her best to get back the man she loves. The Avengers are charged with taking care of the unknown man who, seemingly, dropped out of the sky. When said man starts to insist he's not from their universe, well, would you believe him?

Post-reveal, established relationship, aged-up