Sasuke could be one of the main characters. He might be suspicious of Naruto's new powers and how they change Naruto. Their relationship could become more complex as Sasuke tries to understand if Naruto is still the same person he knew.
Kakashi could also play a major role. As Naruto's teacher, he would be concerned about how Naruto's new identity affects his ninja training and his future as a ninja. He could try to guide Naruto in using his powers in a way that doesn't disrupt the ninja world too much.
Well, Sasuke is likely to still be a main character. His relationship with Naruto would be even more complex if Naruto is the son of Apollo. He might be jealous of Naruto's new powers or intrigued by them. Another could be Kakashi. He would play a role in guiding Naruto in understanding and controlling his powers inherited from Apollo.
Sakura might also play an important role. She could be one of the first to notice the changes in Naruto due to his divine connection. Maybe she tries to help him understand and control his newfound abilities, while also dealing with her own feelings for him in this new context.
Another main character could be Kakashi. As Naruto's mentor, he would have to guide Naruto in understanding and using his powers related to being Raizen's son. He might also be the one to protect Naruto from those who would seek to harm him because of his new identity.
Well, in addition to Naruto, Gaia herself could be considered a main character in a sense, even if she might not be a physical presence all the time. If the fanfiction delves into Naruto's heritage, there could be other characters related to Gaia's past or other 'sons' or 'daughters' of Gaia in the Naruto world. And of course, Naruto's friends like Sakura would also be important. Her reaction to Naruto's new identity could range from shock to being supportive, and she might be involved in Naruto's new adventures related to his connection to Gaia.
Samul, of course, since he's Naruto's supposed father in this fanfic. He could be a powerful ninja who had some great influence in the past. Another character could be Naruto's mother, who might have a different story now considering her relationship with Samul. Also, characters like Jiraiya could still play an important role. He might be the one to guide Naruto in understanding his new identity as Samul's son and help him train to face the challenges that come with it.
Gohan himself could be a main character in some form. Maybe he exists in Naruto's memories or as a spirit guide. Another potential main character could be Sakura. She might be interested in Naruto's new powers and try to help him understand and control them. And of course, there could be new characters introduced from Gohan's world that interact with the Naruto characters.
Bulbasaur - girl might be a great choice too. Her connection with nature and plant - based attacks could add an interesting dynamic. She could help Naruto understand the Pokemon world better, especially when it comes to things like finding herbs or dealing with forest - related challenges. There could also be a fiery - tempered Charmander - girl who provides a contrast to Naruto's more easy - going nature and has her own set of powerful fire - type attacks.
There could be Sasuke. Since Naruto's situation changes, Sasuke might play a different role in this fanfic, either as an ally or a rival in a new way. Another might be Kakashi. He could be the one guiding Naruto through his discovery of being the son of chaos.
One of the main characters could be Fleur Delacour. Since she's from Beauxbatons, she might be the one to first interact with Naruto. She could be curious about his strange abilities and help him adjust to the school. Another could be a male student at Beauxbatons who is initially jealous of Naruto getting all the attention but later becomes his friend after seeing his true character.
There could be a leader of the horde. This character might be initially skeptical of Naruto but later comes to respect him. Another character could be a young member of the horde who looks up to Naruto as a role model and wants to learn from him.