His personality might become more aggressive. The demon nature could bring out his primal instincts, making him less patient and more prone to anger.
When Naruto becomes a demon in a fanfic, his personality could change in multiple ways. He might become more solitary as he feels like an outcast. His usual cheerful and optimistic nature could be replaced with a sense of brooding. He may also develop a more self - centered attitude as he struggles to come to terms with his new form and the powers that come with it. But at the same time, he could still retain some of his core values deep down.
If Naruto turns into a demon in a fanfic, his personality is likely to be greatly affected. He could become more secretive, hiding his new demonic self from those he cares about. His sense of humor might disappear as he is burdened by his new state. He may start to question his identity more. For example, he might wonder if he's still the same Naruto who wanted to be Hokage. His relationships would be strained as his new personality traits clash with those of his friends. However, over time, he might learn to integrate his old and new personalities and become a more complex and evolved character.
He might become more cynical. Instead of seeing the good in people like he used to, he starts to suspect everyone's motives. For example, he may no longer trust his friends easily.
Naruto might become more calculating. Since Mewtwo is very intelligent and has powerful psychic abilities, Naruto would have to use his mind more. He would think before acting, unlike his impulsive self in the original series. This change could make him a better strategist in battles, but it could also lead to misunderstandings with his friends who are used to his more straightforward and impulsive nature.
Naruto's personality could shift towards being more reserved. As a Shinigami, he has to deal with the weight of handling souls and the concept of death. This could make him think twice before acting impulsively like he used to. He may also develop a more empathetic side towards those who are about to die or have lost loved ones, as he now has a closer connection to the afterlife.
His once optimistic and determined personality would turn cynical. Instead of seeing the good in people, he would suspect everyone. For example, he would no longer trust his friends easily. His sense of humor would disappear, replaced by a cold and sarcastic attitude. He would become more secretive and withdrawn, not sharing his thoughts and feelings like he used to.
If Naruto becomes a Hunter Nin in fanfiction, his personality would change significantly. He'd be more calculating. His usual impulsive nature would have to be toned down because one wrong move as a Hunter Nin could mean disaster. He might also become more solitary, used to working alone in the shadows rather than in a team. His sense of humor might also be more subdued as he takes on this serious and dangerous role.
He might become more serious. He realizes the weight of his responsibilities, so he's not as carefree as before. But he still tries to keep his positive and determined attitude.
His positive and determined personality would turn into a cynical and cruel one. He might lose his sense of justice and become self - centered.
His personality would become more reserved. As an assassin, he couldn't be as open and friendly as he used to be. He'd have to keep his emotions in check to avoid being detected.
Naruto's personality would become more brooding. He would be less impulsive and more calculating, like Batman. He might not be as openly friendly as he was before, keeping his thoughts and plans more to himself.
His character might become more isolated. With the power of the Juubi, Naruto may feel that he's on a different level from his friends. He could also become more cautious as he has to control such a huge power.