One of the main characters could be Hinata. Since she has the Byakugan, a fanfiction might explore the idea of her evolving it into a godlike doujutsu. Another character could be Madara Uchiha. His return in some form and obtaining a godlike doujutsu would be an interesting plot point. And of course, there could be mysterious, unnamed characters that are the center of the story in the fanfiction, with their godlike doujutsu being the main focus.
Naruto Uzumaki is often associated as he has ties to the Namikaze clan through his father. He could be a central character in exploring the Namikaze clan doujutsu, either as a potential wielder or someone trying to understand it. Another could be Minato Namikaze, Naruto's father. His own abilities and knowledge could be crucial in uncovering the secrets of the clan's doujutsu.
Sasuke can also be a central figure. His quest for power in the original Naruto makes him a prime candidate in fanfictions about godlike chakra. He might either gain it on his own or be in a rivalry with Naruto over it, leading to intense battles and power struggles.
Naruto himself is often involved. His strong will and determination could make him either a target of hypnosis or someone who has to resist it. Sasuke is also a likely candidate, given his powerful doujutsu, the Sharingan. Hypnosis could potentially be used to manipulate his actions or unlock hidden aspects of his Sharingan powers.
Naruto himself is often associated with it. Since he is the main character of the series, many fanfictions explore his potential with the Lightning Armor. He might learn to use it in unique ways, like combining it with his Rasengan.
Naruto himself could be one of the main characters associated with it. Since he has such iconic spiky hair, it's easy to imagine him developing some unique hair jutsu. Sakura might also be involved, as her long hair could be used in interesting ways in fanfiction. And Sasuke, his cool and somewhat long hair could also be a factor in hair jutsu - related stories.
Sasuke might also be a main character in such fanfiction. His Sharingan and his own strong chakra could potentially be used in relation to the chakra arrow. He could use his Sharingan to predict the path of the chakra arrow or enhance its power.
Sasuke is often a character associated with black chakra in fanfiction. Given his natural inclination towards power and his dark past, it's easy to imagine him being connected to such a powerful and mysterious form of chakra.
Often, Naruto himself might be associated with it. Writers could explore the idea of Naruto unlocking the Celestial Release as a new power, perhaps during a time of great need in the story. This would give him an edge against powerful foes.
Often, Naruto himself might be associated with it. Since he has a large amount of chakra and is always looking for new ways to fight, the chakra bow could be something he discovers or is given. Another character could be Sasuke. His Sharingan might give him a unique advantage in using the chakra bow, like being able to accurately aim at distant targets.
Often, Naruto himself might be associated with it in some fanfictions. Given his status as the protagonist, it's not uncommon to give him such a powerful ability. Another could be Sasuke, as his power - hungry nature in the original series could be explored further with the God Release.