The main character is Naruto for sure. Alongside him, we can expect to see many familiar faces from the Naruto series. Sasuke is likely to be a key character as his relationship with Naruto has always been a major aspect of the story. Characters like Jiraiya, who was Naruto's mentor, could also make an appearance, perhaps as a guiding spirit to Naruto in his role as the eternal king. And of course, villains from the original series might resurface in new forms to oppose Naruto's eternal rule.
In the 'naruto the eternal king fanfic', Naruto is the central character. However, his friends from Team 7, including Sasuke and Sakura, are probably going to be main characters too. Additionally, characters from other villages such as Gaara from Sunagakure might be involved. They could be important in terms of international relations in the story where Naruto is the eternal king. Also, there might be new characters introduced who are specifically related to the concept of Naruto being an eternal king, like advisors or enemies who only exist because of his new status.
Given that it's a Naruto - based fanfic, Naruto Uzumaki might be one of the main characters. He could be the one who discovers the existence of the eternal guardians. Sasuke could also be involved, perhaps in a conflict or alliance with these guardians. And if the fanfic focuses on the shinobi world as a whole, characters like Kakashi or Tsunade might also play important roles. As for the eternal guardians themselves, they could be unique characters with their own personalities and powers.
There could be an original character created specifically for this fanfic. This character might be the one who actually has the eternal rinnegan and is central to the story. Their backstory, motives, and relationships with other Naruto characters would drive the plot forward.
Another possibility is that it could involve Naruto as a main character even though he doesn't have the Sharingan. His relationship with the character having the Eternal Sharingan could be explored. Maybe Naruto helps the character come to terms with their power or they team up to face a common enemy. This would add an interesting dynamic to the fanfic as Naruto's ideals and the power of the Eternal Sharingan collide and combine in different ways.
Since it's related to Naruto, Naruto himself is most likely a main character. He is the one becoming the eternal emperor.
Obviously Naruto is one of the main characters since it's in the title 'naruto is king fanfic'. He is likely to be the central figure around which the story revolves.
I can't say for sure without reading it, but Naruto is likely to be a main character given the title. There may also be some original characters created for the Western setting, like a Western - style mentor for Naruto or an antagonist who opposes his claim to be the king of the west.
Obviously, Naruto is one of the main characters since it's in the title. He's in the role of the 'king of shadows'. There might also be his usual friends like Sasuke and Sakura, but they could have different relationships with Naruto in this fanfic because of his new status.
Well, Naruto is the central figure. Then, there might be a group of unique bandits who are his loyal followers. They could have different abilities and personalities. There could also be a female character who has a special relationship with Naruto, either as a love interest or a strong ally. And don't forget, there may be some antagonists from the traditional ninja world who view Naruto's bandit king status as a threat and try to stop him.
Naruto is surely one of the main characters. Since it's related to Naruto, he would be at the center of the story.
It could be about Naruto achieving a status of an eternal king in some sort of alternate universe or fan - created storyline. Maybe it shows Naruto ruling over Konoha or the entire ninja world for an eternity, with new challenges and adventures related to maintaining his eternal reign.