Even an older Uchiha like Itachi (in a non - villainous AU perhaps) could be a mentor. The Uchiha are known for their fire - based jutsu. Itachi could teach Naruto the subtleties of fire control, like how to vary the intensity and shape of the flames for different combat situations.
An older, more experienced ninja from a hidden village that specializes in needle - based jutsu could become his mentor. This ninja could have unique insights into the art of using needles, teaching Naruto different formations and strategies for using them in battle.
He might face powerful rogue ninjas. These ninjas could be after the power of the black fire for themselves. They would see Naruto as a threat and try to take him down to get the power.
It could be Kakashi. He has a vast knowledge of different jutsus and could help Naruto understand the fundamentals of controlling the Ice and Wood Release. Kakashi might use his Sharingan to analyze how Naruto's chakra is flowing when he tries to use these new abilities.
Sasuke could be Naruto's parkour mentor. Despite their past differences, Sasuke has great skills in movement and agility. He could teach Naruto more refined parkour techniques, like how to land more quietly or how to make sharper turns while running on rooftops.
Even though Orochimaru is a bit of a controversial figure, in a fanfic, he could be Naruto's mentor in a different way. Maybe Naruto tries to learn from Orochimaru's vast knowledge of jutsus, but at the same time, he tries to correct Orochimaru's wrongdoings. This would be an interesting dynamic as Naruto tries to take the good parts of Orochimaru's Sannin - like qualities while avoiding the evil.
One potential mentor could be an older and experienced samurai who has seen many battles. This samurai could teach Naruto the traditional ways of the samurai, like proper swordsmanship and the code of honor. Another could be a former ninja who has transitioned into samurai - like combat. They would understand Naruto's ninja background and be able to help him bridge the gap between his two forms of training. Maybe a samurai from a far - off land who has unique fighting styles and philosophies could also be a mentor, introducing Naruto to new ways of thinking about combat and honor.
One potential ally could be Hinata. Hinata has a very gentle and empathetic nature. She could help Naruto by using her Byakugan to be his 'eyes' and describe the world around him. For example, in battle, she could tell him where the enemies are. Another could be Kakashi. Kakashi is a very experienced ninja. He could develop special training methods for Naruto that are more focused on his remaining senses. He could also use his Sharingan to sense threats and communicate that to Naruto in some way, like through a series of taps or vibrations.
Jiraiya could be one of his mentors. He's already Naruto's teacher in many ways and has a vast knowledge of different ninjutsu, so he would be a great choice to teach Naruto about elemental ninjutsu. Another potential mentor could be Kakashi. He's known for his wide range of skills and could pass on his knowledge about elements to Naruto. Also, Tsunade might be a mentor. She has great control over her chakra and could teach Naruto how to use his chakra more effectively for elemental ninjutsu.
Well, first of all, Gai Sensei could be an excellent mentor for Naruto in martial arts. He is extremely passionate about taijutsu and has a lot of unique training methods. Kakashi could also play a role as a mentor. He has a diverse set of skills and could introduce Naruto to some rare martial arts techniques he has learned over the years. And then there's Tsunade. Her strength in close - combat and knowledge of physical combat could make her a great martial arts mentor for Naruto.
In this fanfiction, Kakashi could also be Naruto's mentor in magecraft. Kakashi is known for his adaptability. He could start to study mage powers along with Naruto. They could learn together about new forms of magic, and Kakashi could use his combat experience to help Naruto understand how to use his mage powers in battle situations.