Well, at first, Naruto would probably start to withdraw from his normal activities. He'd stop going on missions and spending time with his friends. Then, he might start having self - destructive thoughts more frequently. As the story progresses, his friends might notice something is wrong, but Naruto would be reluctant to talk about it. Eventually, if no one can reach him in time, he could attempt something dangerous to himself.
In the beginning of this kind of fanfic, Naruto could be shown as being haunted by his inner demons. He might start having nightmares and become more irritable. As time goes on, he begins to isolate himself even from his closest friends like Shikamaru or Sakura. His chakra control could start to falter as his mental state deteriorates. His friends would gradually realize the severity of the situation and try to find a way to snap him out of it, but it would be a difficult and long process.
If Naruto becomes ruthless in a fanfic, the story development would be very different from the original. His character arc would no longer be about growth through friendship and perseverance. Instead, it could be about his descent into a more power - hungry and cold - blooded state. The plot might focus on how the other characters react to this new Naruto. Some might try to stop him, while others might be forced to follow him out of fear. His relationship with Hinata could also be severely affected. She might be heartbroken by his change and try to reach out to him, but he might reject her, creating a very emotional and complex sub - plot.
Well, one way could be that Naruto starts to study the samurai code. He might learn about bushido, the way of the warrior. He could be inspired by samurai values like honor and loyalty. This could lead to him incorporating samurai techniques into his fighting style. For example, he might use a katana - like weapon in combination with his shadow clone jutsu. It would be really interesting to see how his relationships with his friends change as he delves deeper into the samurai world. Maybe he would make new friends among the samurai clans too.
The story could develop with Harry introducing Naruto - style training methods to Hogwarts. This might include physical conditioning similar to what ninjas do. His friends could be both confused and excited about this new approach.
Their relationship could start with Kurenai being cautious around Naruto as he is now the Kyuubi. But as she sees his struggle to control the power and his good intentions, she warms up to him. She might become a mentor - like figure, guiding him on how to use his new abilities for the greater good. And Naruto would respect her for her knowledge and kindness, leading to a strong bond of trust between them.
In such a fanfic, it might be due to a false accusation. Suppose Naruto is wrongly accused of a heinous crime like mass murder in the village. Everyone turns against him, and he has no way to prove his innocence. This overwhelming sense of injustice and isolation could drive him to suicidal thoughts. Also, if he discovers some dark secrets about his past, such as his parents' real cause of death being related to some sort of betrayal he unknowingly caused, it could break his spirit.
If Naruto becomes a Hidan fan in fanfiction, the story could develop in many ways. For one, Naruto may start to distance himself from his normal friends and allies as he delves deeper into understanding Hidan. He could form new relationships with characters who have a more lenient view of Hidan's actions. This would lead to a split in the ninja community, with some supporting Naruto's new perspective and others trying to stop him. The story could also explore how Naruto's view of the world changes as he starts to see things from Hidan's point of view, and how he might try to incorporate some of Hidan's ideas into his own ninja way, which would be a huge departure from his original beliefs.
In the fanfic, Sora's suicidal tendencies would force Kairi to be more assertive in their relationship. She would actively seek ways to heal his broken spirit. For example, she might take him back to the Destiny Islands to relive their happy memories. Sora, feeling Kairi's love and care, would slowly let go of his self - destructive thoughts. As a result, their relationship would grow stronger. Kairi would become Sora's anchor, and Sora would learn to value himself more because of Kairi's presence in his life. Their relationship would no longer be just about a shared past but also about building a future together.
Naruto might become more confident, but also more cautious. The power of the Juubi is immense, and he would need to be careful not to let it corrupt him. He could also become more of a leader, as his power would make him a key figure in the ninja world.
The story could develop with Naruto having to adapt to his new form. He would have to learn how to move and use the Kyuubi's powers in this new world. Maybe he would start by hiding in the wilderness to avoid being detected.
One possible way the story could develop is that the members of Team Seven gradually notice the reader's suicidal tendencies. Naruto, being the energetic and empathetic one, might try to cheer the reader up by sharing his own dreams and how he overcame hardships. Sasuke, although aloof, could show concern in his own way, perhaps by silently protecting the reader during a mission. Sakura, with her medical knowledge, could be the first to notice any physical signs of the reader's distress and try to get to the root of the problem.