One popular theme is 'alternate universes' where the story takes place in a different setting than the original anime. For example, the characters might be in a modern - day high school instead of a fantasy world.
The parental review on FanFiction.net mainly focuses on factors like language, violence, and mature themes. It aims to give parents a clear idea of whether the content is appropriate for their children's age and maturity level.
The longest running fanfic on FanFiction.net is a constantly evolving thing. Different genres and fandoms have their standout long-running stories. Sometimes it's a romance fic, other times it could be an adventure. It really varies!
Pretty much. Fanfic.net is known for being a place where most of the content is fanfiction. However, there might be a rare exception or two, but the vast majority of what you'll find there is related to fan-created stories based on popular franchises.
Sometimes fanfiction disappears because the author lost interest or faced legal issues. It can also happen if the hosting platform shuts down or removes the content.
Archive of Our Own (AO3) is a great alternative. It has a more inclusive and diverse range of fanfiction. It also has a better system for categorizing and tagging stories. Another alternative is Wattpad. While it has a mix of original and fan - based content, you can still find some good fanfiction there. Additionally, Tumblr can be a source of fanfiction, especially if you follow the right blogs.
Well, some might be about fantasy adventures with original characters in a unique world. For example, there could be stories of a brave knight in a magical land full of strange creatures.