The owner of the local ramen shop could also be a main character. They could be constantly coming up with new and crazy ramen flavors for Naruto to try. And there could be a mysterious ninja who has a connection to some of the special foods Naruto eats. This ninja could be either a friend or a foe, depending on the plot.
Well, Naruto is obviously one of the main characters since it's in the title. He's the one doing all the eating. There might also be his friends like Sasuke and Sakura. Sasuke could be annoyed by Naruto's eating habits, while Sakura might be worried about the effects of all that eating on Naruto's health.
Obviously Naruto himself would be a main character, in his dark form. There might also be other characters like Sasuke. Sasuke might be in a position of either trying to stop Naruto or joining him in his dark deeds. And Sakura could also be there, perhaps as a voice of reason trying to bring Naruto back from the darkness.
Obviously Naruto is one of the main characters as it's in the title. But there might also be his friends like Sasuke and Sakura. They could play important roles in the story, either as Naruto's sidekicks or as characters who are also influenced by Naruto's god - like nature.
Most likely Naruto would be the main character since it's about him being a master of everything. But other characters like Sasuke, Sakura, Kakashi might also be important as they could be involved in Naruto's journey of achieving this all - round mastery.
Perhaps Naruto eats a magical food item that gives him a temporary power boost. He could then use this newfound strength to compete in a local ninja tournament. This would make for an exciting plotline as his opponents are caught off - guard by his sudden increase in power.
The Princesses, Celestia and Luna, are likely to be part of it. They might be the ones with the knowledge or power to help Twilight. Celestia could offer her wisdom on how to control this new and dangerous ability, while Luna might use her connection to the night and dreams to figure out if Twilight is under some sort of spell.
It could be a powerful spirit that is enraged by Naruto's soul - eating. This spirit might have been protecting the souls in the first place and now sees Naruto as a great threat.
In addition to the original Naruto characters, there could be new characters introduced in the fanfic. Maybe a mysterious sage who has some connection to Naruto's all - knowing ability. However, the main focus would still be on Naruto and his friends from the original series. His knowledge would change the dynamics between them. For example, Naruto might know things about Kakashi's past that could strengthen their bond or create some interesting plot twists.
It could be someone from Naruto's past that he had forgotten about. Maybe a former rival from his academy days who felt overshadowed by Naruto and now that Naruto remembers everything, including some secrets about this person, they become the antagonist. This person might try to stop Naruto from using his new - found knowledge to gain more power or influence in the village.
The plot might involve Twilight being cursed or tricked into this 'eats the everything' state. She might start by accidentally consuming small things like flowers or books, which gradually grow into bigger things. And as she eats more, it affects the balance of the world around her, causing her friends to worry and try to find a way to reverse it.
In the 'the night eats the world novel', the primary character is a man. He is an ordinary person who wakes up to a nightmare. He has no special powers, just his wits and whatever resources he can find in his building. While we don't really get to know many other characters in great detail, as the story is mainly about his solitary struggle for survival. He is constantly facing the challenges of the new world on his own, and his character development is about how he copes with this new, terrifying reality.