Hermione could be a main character. She would probably be very involved in helping Harry with the baby, using her vast knowledge of magic to ensure the baby's well - being.
The characters might be reimagined with different values. For instance, Hermione could be more conflicted about her pursuit of knowledge. In 'A Brave New World', knowledge is often restricted based on one's social caste. So in this fanfiction, Hermione might face more opposition when she tries to access certain books or magical knowledge. She could start to question whether her thirst for knowledge is really a good thing in this new, more controlling magical society.
James Potter often makes an appearance. Since he was Lily's husband, his relationship with both Harry and Lily is explored in different ways. For example, in some fanfictions, Harry gets to see a side of his father through Lily's memories that he didn't know before.
Harry could be seen as a strange but powerful being. His Gryffindor courage would be respected in Asgard. Hermione might be seen as a great scholar, like the Asgardian mages. Ron could be the loyal friend who has to adapt to the grandeur of Asgard.
One main character could be Griphook. He already has a complex relationship with Harry Potter in the original series. In a goblin rebellion fanfiction, he could be a key figure leading the goblin revolt, using his knowledge of the wizarding world and his own skills to strategize against the wizards. Another character could be a young goblin apprentice who is caught between his loyalty to his own kind and his admiration for Harry Potter and the wizarding world.
One possible main character could be a Martian elder who takes Harry Potter under their wing and helps raise him. This Martian elder could have special knowledge about the planet and its hidden magic that they pass on to Harry.
She would be far more unpredictable. The original Harry was quite noble and adhered to a set of moral values. A female Harry raised by the Joker might not have such a clear - cut sense of right and wrong. She could be more likely to play pranks and use her magic in ways that are not strictly 'good'. For example, she might use magic to create chaos in a situation just for the fun of it, rather than to solve a problem in an orderly manner like the original Harry.
I recommend the following novels to you. They are all Harry Potter Doujinshi novels with female protagonists! They were "Leisure Life at Hogwarts,""HP Doujinshi: Reversal," and "Lily from HP." The Hogwarts leisure life was about daily life. The protagonist thought that he could live a leisurely life in the Harry Potter world, but he found out that it was not. HP Doujin: The purpose of reversing the main character is to reverse the direction of some of the characters in the original work. Want to see how the female protagonist changes the fate of Harry Potter? The last book, Lily, was a time-travel novel with James Potter's wife, Lily Potter, as the main character. It told the story of her facing the death of her husband and the growth of her daughter. I hope you like my recommendation. Muah ~
I don't know for sure as I haven't read this particular fanfic. But it could feature some original characters along with well - known 'Harry Potter' characters. Maybe it focuses on a new student who has been living in the shadows and Harry and his friends gradually get to know this person.