Sasuke is often a main character in such fanfictions. He could be Naruto's right - hand man, using his skills and intelligence to support Naruto's rule. Their relationship might be more complex, with Sasuke having to come to terms with Naruto's new position of power.
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.
The demihumans themselves would be important characters. There could be a demihuman leader who Naruto teams up with.
Kakashi could play an important role. His experience and wisdom would be valuable in strategizing against the gods. Additionally, characters like Jiraiya might make an appearance, perhaps guiding Naruto from the afterlife or having left some knowledge that helps Naruto in his defiance. Another character could be Gaara. His unique abilities could be crucial in fighting against the gods' minions.
Kakashi is likely to be a main character too. As Naruto's former teacher, he could be guiding Naruto in the ANBU or having some sort of conflict with the ANBU higher - ups over Naruto's training and assignments.
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.
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.
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.
There could be the princess of Altomare. She might play a crucial role in helping Naruto understand the city and its needs. Also, some of the local fishermen or sailors could be main characters as they are likely to be affected by any threats to Altomare and could assist Naruto in his guardian duties.
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.
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.