This counts for anything that is a comic. Superhero, or otherwise. Homestuck included.
But if the Comic the character comes from has many spinoffs, please tell me which you intend them to be from, and do not base them completely off of a movie counterpart (seeing as, I think say, the Joker from Dark Knight was different than our average Joker. Good example?). I don’t think I’ll be allowing Movie/TV Series characters yet. It would be entirely too hectic. No one would know who to choose, and fights could occur.
Though since this AU, you can do what you want with characters, as I did with Julius. Just try to loosely stick to canon, since that makes the most sense.