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.
Well, Vegeta would be a likely character. He might be initially suspicious of the female Goku. Maybe he thinks she's a threat or just can't believe there's another Goku - like being. He could be there to add some comical moments as he tries to understand the situation.
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.
In general, it's a bit of a toss-up. The strength of Manga Goku and Anime Goku can vary depending on the specific arcs and battles. Sometimes, it might seem like one is stronger in a particular situation, but that could change in another.