I was searching for some fun Novels to read, and I got Master of Marvel World, a Fan-fiction. Just like this, I want some Fan-fictions, where MC have encountered something unexpected, and now is inside Anime, Novel or, Game world. I don't care about MC's personality, but at least he must not be dumb. Most of the Fan-fictions have Harem. So, I too want some good Harem stuff, where girls are of some popular Manga or, Anime.(if there is some erotic stuff then it's will be awesome) Male Protagonist is must. Obviously no to Yaoi. Just a normal typical Harem. Suggest some Fan-Fiction, an enjoyable Novel to make my mind fresh.
I am a Gao Fushuai Villain is pretty interesting However I have to warn you that in my experience fan-fictions tend to be worse than originals (in general, not specifically the original of the fan-fic) in over 90% of cases
Try Shoujo Grand Summoning. Although the early romance are pretty bad(don't ask me why), from then on it will become better. Wait... Are you reading mtl?
Don't know why most of the fan-friction I have read are all related to Marvels. Everyone really like marvels a lot. I like it too though