You can promote your fan-fiction work and look for other authors to help you.
All kinds of fan fic are allowed such as : Harry Potter, Sherlock, Doctor who, Supernatural, Anime and etc.
Sherlock, Harry Potter, Doctor who, Supernatural, Hunger games, Anime and etc. have lots of fans and they mostly write fan-fiction about these characters so this group is for those fan-fiction writers who want to promote themselves or need help or looking for some collaborative authors.
If you can dream it, you can do it.