Yes, the Bnha manga has finished. The final chapters wrapped up the plotlines and brought closure to the series. It's been quite an adventure for fans.
Some characters in bnha scary stories are unique to those stories. These new characters are often created to add to the spooky or suspenseful atmosphere. They might have really strange or terrifying quirks that we don't see in the main series. For instance, a character with a quirk that allows them to manipulate shadows into terrifying shapes that can attack people. So, in many ways, they are different from the characters in the main series.
Some powers might need to be toned down. For example, Todoroki's ice and fire powers could cause a lot of damage in the real world. He'd have to learn to control them more precisely so as not to cause destruction. And some powers might be more useful in unexpected ways. Uraraka's zero - gravity power could be used for things like helping with construction or moving heavy objects in a safe way.
Well, 'bnha' is short for 'Boku no Hero Academia'. Fanfic means fan - made fiction. However, the term 'cocksleeve' makes this seem like it could be something inappropriate or not in line with the general positive and family - friendly nature of the 'My Hero Academia' fandom. It might be some sort of very niche, and perhaps not so appropriate, fan - created story within the BNHA community.
In some BNHA fanfics, Kaminari might be portrayed as the traitor, but it really depends on the specific plot and the writer's creativity. There are various interpretations in the fanfic world.