He might become more reserved. Kakashi is often a bit aloof and mysterious, and wearing the face mask like him could make Naruto act in a more subdued way, not showing his emotions as openly as he usually does.
His leadership style could change. Normally, Naruto is very energetic and upfront in leading his team. But with the mask like Kakashi, he may start to lead more from the shadows, guiding his teammates in a more subtle and strategic way, similar to how Kakashi often does things without being too obvious about his intentions.
Well, obviously, the addition of the face mask gives him a more mysterious look. His usually open and friendly face is partly hidden, which might make others view him with more caution or curiosity.
Another possibility is that Naruto wears the mask as a tribute to Kakashi after a significant event. It could be that Kakashi sacrifices himself to save Naruto and the village. So, Naruto dons the mask to carry on Kakashi's legacy and to always remember the lessons he learned from him.
Naruto's personality might show a more serious side. Wearing a suit could make him feel more responsible, like he has to represent the Hidden Leaf in a proper way. So he'd be less likely to crack jokes and more focused on the task at hand.
Perhaps in this fanfiction, there's a specific mission or situation. Maybe they are on a stealth mission together, and Naruto decides to wear a face mask like Kakashi to blend in better or to follow some kind of ninja code that Kakashi has taught him for this particular task.
In such fanfiction, Naruto's personality could be a mix of his old self and a new, more complex version. He would still be the determined and kind - hearted Naruto at heart. However, the power of the hollow mask might make him more secretive. He might keep things from his friends and mentors for fear of them trying to take the mask away. This internal conflict between his old and new self could be a major part of his character development.
If it's a more spiritual fanfiction, the mask could have a connection to the spirit world. Naruto wearing the mask could open a portal to that world or allow him to communicate with the spirits of past ninjas. He could then seek advice from the great ninjas of the past through the power of the mask.
He might become more withdrawn. The burned face could make him self - conscious, so he doesn't interact as freely as before. For example, he might avoid public gatherings or eye contact with people.
He might seem more studious. Wearing glasses could give the impression that he's more into reading and learning new jutsu. So he could be seen spending more time in the library or with his sensei, trying to understand complex ninja techniques.
One possible reason could be for disguise. Maybe he is on a secret mission and doesn't want to be recognized easily. In the Naruto world, there are many dangerous foes, and wearing a face mask can help him blend in or hide his identity from those who might be targeting him.
He'd probably be more reserved. Kakashi is not as boisterous as some others, so Naruto might pick up on that. For instance, he might not shout as much about becoming Hokage right away.