He would develop a new side to his personality. His loyalty to Konoha would be expressed in a different way. Instead of fighting on the front lines, he's gathering information in the shadows. This could make him seem a bit more mysterious to his friends. He may also become more adaptable, as he has to fit into different situations and cultures when on spying missions.
Naruto would need to be more calculating. As a spy, he can't just rush into battles like he usually does. He has to think several steps ahead. He might start to analyze situations more deeply, like how his enemies' actions could be part of a larger plan. He also has to be more aware of his surroundings at all times, always on the lookout for potential threats or clues.
His character would become more secretive. Instead of being the open - hearted Naruto we know, he'd have to keep things to himself. For instance, he couldn't share all his thoughts and experiences with his friends right away.
Perhaps he would change to Naruto Storm. 'Storm' can represent his powerful and sometimes tempestuous nature. In the series, Naruto has shown great strength and determination that could be likened to a storm, which is both destructive and at the same time a force of change.
Clothing changes can also represent his emotional state. If he's wearing something more somber and dark, it might indicate a period of self - reflection or dealing with a difficult situation. For example, after a major battle where he loses a friend, he could change into all - black clothes as a sign of mourning.
At first, Naruto might become more secretive. He'd be hiding his new 'profession' from his friends, which is very different from his usual open - natured self. This could cause some internal conflict as he doesn't like lying to them.
Naruto's view of himself and his purpose in life could also change. He might start to question his identity as the Jinchuuriki of the Nine - Tails. With new DNA - based powers, he could feel like he has a different role to play in the ninja world. He might explore new ways to use his powers for the greater good, which would be a significant development in his character.
His confidence could turn into over - confidence bordering on arrogance. As a villain, he might think he is above everyone else and that his way is the only right way. He would no longer listen to advice or consider the consequences of his actions on others, believing that he can handle any situation on his own, no matter how dangerous or unethical.
If Naruto was his father, the Third Hokage might have a different approach to leadership. Naruto was all about unity and bringing people together. So, the Third Hokage could be more focused on building strong relationships between the clans in the village, rather than just maintaining the status quo. He might also be more adventurous in his policies, taking risks to improve the village like Naruto did in his own time. And his fighting style might be a bit more unorthodox, influenced by Naruto's creative use of jutsu.
If adopted by Shino in fanfiction, Naruto's character could change in several ways. For one, he'd likely become more attuned to nature, since Shino has a strong connection to the bugs in nature. Also, his fighting style might become more strategic and less brute - force - oriented. Shino could teach him to use his surroundings and opponents' weaknesses better. And Naruto's sense of family might shift. Instead of always longing for the acceptance of the village as a whole, he'd have a more personal family unit with Shino, which could make him more content and less desperate for validation from others.
It could also be due to a prophecy or some sort of spiritual guidance. In the Naruto universe, there are often prophecies that guide the characters' actions. A prophecy might suggest that changing his name would bring about some great change or power. For instance, if there was a prophecy that a new name would help him unlock a hidden power or unite different ninja clans under a new banner.
Maybe a plot where Naruto's change in gender affects his relationships. His friends like Sasuke and Sakura might react in different ways. Sasuke could be more protective, or Sakura might see her as a new kind of rival or friend. Also, Naruto's relationship with his mentor Kakashi could change as Kakashi has to adapt to training a female ninja with Naruto's unique abilities.
Well, one big change could be in his self - confidence. Naruto already has a lot, but becoming a Jounin is a huge accomplishment. He'll probably be more self - assured in his abilities, which could lead to him taking on more challenging missions. Also, his relationships with his friends might shift a bit. They'll see him in a new light as a higher - ranked ninja, and he'll have to balance his new status with his old friendships.