The Legend of Aang: The Last Airbender
Its a movie sequel to the original Avatar (animated) show, and a prequel to the Legend of Korra series. So I guess an 'interquel' or whatever. It takes place after Aang is an adult and the characters have all moved on to be adults Im assuming in their 20s.
None of the same voice actors return, probably because the kid who played Aang is likely in his 30s now or something, but it had a good cast, Ken Jeong as the cabbage cart guy, Stephen Yeun as Zuko, François Chau as Gyatso in a bit part, Ke Huy Qwan and even Taika Waititi show up here and there.
It honestly felt like a continuation of the show's lore, though Im not sure if it counts the two comic series that came after the show as canon, because there's no mention of the events therein that Im aware of. You could tell it went into 3D animation at some points for the characters, but it wasn't super jarring. Easy to get past, but its there.
The main villain is pretty much telegraphed as soon as you meet them which is to be expected. What show/movie introduces a new character and it doesn't end up being a villain? (unless they leave and die on the way to their home planet, a la Poochie) Otherwise its not a bad flick. Lots of the same humor, anime-esque influence like the original show, and almost as much heart as the original show. Even Momo got a cool little scene. A nice ending even though it might contradict the second Korra series, but honestly I dont know if they count Korra as part of the story anymore. Whats neat is even with different voice actors, all of the 4 main character personalities come through as if it were the next episode in the series.