The scientists or those responsible for the experimentation could be key characters as well. They would drive the plot forward by their actions and decisions regarding the female Naruto, and their motives for the experimentation would be a crucial part of the story.
Obviously, a female version of Naruto would be the main character. She would be at the center of the story, dealing with the consequences of the experimentation.
Obviously Naruto and the fem Kyuubi would be the main characters. Naruto is the one being corrupted and the fem Kyuubi is the one causing the corruption.
Obviously, fem Naruto herself is a main character. Her father, Minato Namikaze, and her mother, Kushina Uzumaki, are the ones she is going to meet. There might also be other characters from the Naruto universe like Jiraiya, who was Minato's teacher and could potentially be involved in the story, perhaps as someone who helps facilitate the meeting.
Naruto himself is obviously a key character in this type of fanfiction. Then there's Sasuke. Given his popularity and complex personality, he can add a lot of drama to the harem situation. Shikamaru is also likely to be part of it. His laid - back but intelligent nature can create interesting interactions with Fem Haku. Another one could be Gaara. His past and his new - found path of friendship could lead to him having feelings for Fem Haku in the fanfiction.
One common theme could be exploring the unique challenges a female Naruto might face in a world dominated by male shinobi. For example, she might have to deal with different expectations regarding her strength and abilities.
Obviously, Fem Percy would be one of the main characters. There would probably also be the leaders or prominent members of the hunt. Maybe some characters from the original Percy - related stories could also make appearances in different roles, like her friends who might be worried about her new path in the hunt.
Obviously Naruto would be one of the main characters. He's the protagonist of the original series and his power and will would be crucial in a doomsday scenario. Sasuke would also be likely, as his strength and his connection to Naruto are important elements. Sakura, with her medical skills, would also be a key character as she could be responsible for healing the injured during the doomsday chaos.
Well, it's possible that some new or less - known characters from the Naruto universe could become main characters in 'chaos naruto fanfiction'. For example, Rock Lee could take on a more central role. He has always been a character full of determination and unique fighting style. In a chaotic setting, his strong will could be a key factor in dealing with the chaos. And then there are the jinchuriki of the other tailed beasts who might be more prominently featured as they are all related to the power dynamics in the Naruto world which could be thrown into chaos.
Obviously, Naruto would be one of the main characters. Since it's a Naruto - centered fanfiction with the beyonder element added. Sasuke could also be a main character as he is often Naruto's counterpart and rival. They might both be involved in exploring the beyonder powers. Additionally, characters like Kakashi could play important roles. He could be the one guiding Naruto and Sasuke in understanding these new and strange beyonder powers, given his experience and wisdom.
There may be new characters introduced as well. Maybe a mysterious figure who has a special ability to either enhance or dampen Naruto's will to live. This character could add an extra layer of mystery and conflict to the fanfiction.
Naruto would be the central figure. But in this British version, there could be new characters added, like a British wizard - type character who becomes Naruto's mentor in understanding the new 'British - ninja' aspects of his life. And of course, Sasuke and Sakura would be adapted to fit the British setting, perhaps with different family backgrounds that are more in line with British culture.