The main character is Naruto. However, in fanfiction, often new characters are introduced. In this 'naruto king of the dead fanfiction', there could be a villain who is trying to take over Naruto's new position as the king of the dead. There may also be some dead shinobi from the past who play important roles, either as allies or as obstacles for Naruto. And his friends from Konoha will likely be part of the story too, as they are an important part of Naruto's life in the original series.
Naruto is surely a main character. Additionally, there might be some original characters created specifically for this fanfiction. For example, there could be a powerful spirit or a guide in the world of the dead who helps Naruto understand his new powers. And characters like Kakashi could also be involved, perhaps providing advice or assistance to Naruto as he deals with the implications of being the king of the dead.
Kakashi could be another important character. As a mentor figure, he might be guiding the younger generation through the difficult times after Naruto's death, using his experience and wisdom to keep the village stable.
It's hard to say for sure as it's fanfiction, but it could feature Naruto himself. He might be on a journey to understand the secrets of the book of the dead. Sasuke could also be involved as he often gets involved in Naruto's important quests. Maybe even Kakashi could be there, guiding the younger ones with his wisdom about the strange new elements introduced by the book of the dead.
Obviously, Harry Potter is a main character. In addition, it's possible that Voldemort could be involved in some way. Maybe Voldemort is trying to take over the role of 'King of the Dead' or is causing chaos in the realm of the dead that Harry has to stop. Neville could also be a significant character, perhaps he has some knowledge or power that is useful to Harry in his new adventure as the 'King of the Dead'.
Obviously Naruto would be one of the main characters. Depending on the plot, Sasuke could also be involved, either as a helper or an obstacle. Sakura might also play a role, perhaps as a healer trying to save Naruto. There could also be new characters created specifically for this fanfiction, like a dark figure who is responsible for Naruto's 'dead man walking' situation.
Obviously Naruto would be one of the main characters as it's in the title that he's 'broken'. And since Akatsuki is dead, they might still have an impact on the story through flashbacks or the consequences of their actions. Other characters like Sasuke could also be main characters as he's often closely related to Naruto's story.
Obviously, Naruto would be one of the main characters. His determination and never - give - up attitude would be very useful in a zombie - filled high school. Sakura could also be a main character, using her medical ninjutsu to try and find a cure for the zombie virus. And Sasuke, with his powerful combat skills, would be great for fighting off the zombies.
Typically in a novel with such a title, the main character could be the dead king in a sense that his death sets off the chain of events. There might also be a young protagonist, maybe a knight or a courtier, who is trying to uncover the truth behind the king's death. There could be a villain as well, someone who benefits from the king's death and is trying to cover up their deeds.
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.
Well, Naruto is likely to be one of the main characters since it's in the title. He would probably be involved in the interactions with the Arrancar King. Sasuke might also be there, as he is a major part of the Naruto story. And of course, the Arrancar King himself would be a central figure, driving the plot forward with his actions and motives.
Since it's a Naruto - related fanfiction, Naruto is bound to be a main character. Regarding the Shadowkhan, there could be a powerful Shadowkhan leader or a group of Shadowkhan who play important roles. Maybe there's a Shadowkhan character who becomes Naruto's ally or rival in his journey to be the king. And of course, Naruto's sensei, Kakashi, might also make an appearance to guide Naruto in this new and strange situation.