Rainbow Dash might also be a main character. She's brave and loves adventure. She could take Fem Harry on some wild rides around Equestria and introduce her to the exciting parts of the world. They might even get into some friendly competitions.
Fluttershy could be an important character too. Given her gentle nature, she could help Fem Harry feel more at home in Equestria. She might show Fem Harry how to interact with the animals in Equestria, which would be a new and interesting experience for Fem Harry.
Perhaps the story could revolve around Fem Harry's struggle to adapt to the very different culture in Equestria. She might have to learn how ponies communicate, their social norms, and at the same time, use her own unique skills from her original world to help the ponies in some way. For example, if she was good at problem - solving in her own world, she could use that to solve a mystery in Equestria that was baffling the ponies.
There could be a young Salem witch named Lily. She befriends Fem Harry Potter and shows her around Salem. Lily could be very knowledgeable about the local magic and help Fem Harry Potter understand the differences between Hogwarts magic and Salem magic.
It could be Draco's female counterpart. In this fanfic, she might be just as competitive and haughty as Draco. She would see Fem Harry as a threat to her own status as the top athlete in their school or in their magical sports league. And she would constantly try to undermine Fem Harry's efforts, whether it's by spreading rumors or trying to get her disqualified from competitions.
His family members might also be important characters. His parents, if they are alive in the fanfic, could be the opposite of Harry when it comes to snow. They might be the ones who want to take family pictures in the snow every year, and Harry dreads those moments. Or a younger sibling who is always excited about snow and can't understand Harry's dislike.
Ron could also be a major character. He might have a hard time accepting Harry as a girl at first. But as the story progresses, he could become more understanding and protective of Harry in this new form. And there could be some really funny and awkward moments between them.
There could be an original character who is a descendant of the Uchiha that somehow ends up in the wizarding world. This character could teach fem Harry Potter about the Uchiha ways. Also, Dumbledore could play a role as he always encourages Harry's exploration of different knowledge, and he might be curious about the Uchiha knowledge that Harry is so interested in.
Voldemort is often a key character. Since Harry is going dark, Voldemort might play a role in either guiding him into darkness or being an antagonist to his newfound dark power. Another common character is Hermione. She might try to save Harry from the dark path he's on, leading to a lot of conflict between them.
Hermione could be one of the main characters. She might be suspicious of Orochimaru's teachings and try to convince Harry that it's wrong. She would be constantly researching about Orochimaru and the type of magic he's teaching Harry to prove her point.
It could be another female trainer who has a very different approach to Pokemon training. Maybe she focuses more on brute force while Fem Harry is more about strategy. For example, this rival might have a team full of strong but less intelligent Pokemon like Machamp and Golem, while Fem Harry has a more diverse and intelligent team. Their rivalry could be based on their different training philosophies and the desire to prove who is the better trainer.
Hermione could be one of the main characters. She might be initially skeptical about Fem Harry Potter's newfound interest in stage magic but then get drawn into it when she realizes it can be a new form of knowledge. Another could be Ron, who might find it all a bit strange but still support Fem Harry Potter out of friendship.