Obviously, Harry as the reborn Black would be a main character. Sirius Black would probably also play a major role, as he's an important part of the Black family. And Bellatrix Lestrange could be another key character, her relationship with the Black family and her own dark nature would create a lot of interesting interactions with Harry in his new identity.
The main characters would surely include Harry who is now a Black. Narcissa Malfoy might be involved as well since she's part of the Black family. She could have a complex relationship with Harry, perhaps seeing him as a way to redeem the family name or fearing his new presence. Then there's Regulus Black. His story and his connection to the Dark Lord could add depth to Harry's new journey as a Black.
Well, Harry is for sure the central character as it's his rebirth that's the focus. In addition to him, there could be his friends from the original story, if they also get involved in his new adventure in the sky world. There might also be some sort of sky deities or powerful entities that serve as antagonists or mentors in this fanfiction. These new characters would add more depth and intrigue to the story.
Obviously, Petunia in the form of reborn Harry would be the main character. Vernon and Dudley Dursley would also be important as they are part of the family. And we can't forget about the wizarding world characters like Dumbledore. He would surely notice some changes in Petunia and might start to investigate. Also, there's a good chance that Hagrid would be involved in some way, perhaps bringing some news or event that would set the story in motion for Petunia!Harry.
Obviously, Harry would be one of the main characters. Given the 'Black' in the title, characters from the Black family like Sirius Black or Bellatrix Lestrange could be important. And of course, Rumpelstiltskin would be a central figure as well. He would be the one causing all the trouble related to the inheritance.
Harry, of course, is central. Sirius is likely to be like a father figure to him. Bellatrix Lestrange could be an interesting character in this scenario. Although she's a bit of a dark character, her presence in the Black family and her strong beliefs could create a lot of drama and conflict. Also, Kreacher, the house - elf of the Black family, would be around Harry a lot, and their relationship could develop in unique ways compared to the original story.
Obviously, Harry Potter himself would be one of the main characters. Since it's about his connection to the Lord Black trial. Sirius Black's presence might also be felt strongly, even if not physically present, as his past and the Black family's reputation are central to the trial. Hermione and Ron would most likely be there too, as Harry's closest friends, providing support and using their intelligence and skills to help Harry through the trial.
Obviously, Deku would be the main character since it's about being reborn as him. But other characters like All Might are also likely to be important. All Might was a huge influence on Deku in the original story, and in the fanfiction, he could still play a crucial role in mentoring the reborn Deku.
Neville could be another character. He might look up to Harry even more in his dragon form, seeing him as an even more powerful protector. Hagrid would be excited to have a dragon - Harry around. He could help Harry understand his new dragon nature. And some of the Slytherins, like Draco, might be jealous or scared of Harry's new form.
Well, obviously the character who is reborn as a Black would be a main character. They would bring a whole new perspective to the Black family dynamics.
Obviously, Harry would be the main character. Since it's about him being a Saiyan. And I think some of his friends from the Harry Potter series might also be important characters, like Hermione and Ron. They could react to Harry's new Saiyan identity in different ways.
Obviously, Harry would be the main character as the title implies. But other characters like Hermione and Ron would also be important. They could either be part of Harry's regime, reluctantly or wholeheartedly, or they could be part of the resistance against his dictatorship.