I recently got rivals of aether and the modding has characters, bosses, and maps. The modding process is rather long but it’s not hard and art is kind of a low bar by default. If your character does get barred from the steam workshop you can still share the file and add that manually like Don’t Starve Together. (which does have 1 weight gain character) i could also see Kazecat’s characters getting added as bosses. (With permission of course)
I am currently designing my own characters (Non WG) but i might make some later.