Well, it could be that Itachi trains Naruto to better control his chakra. Maybe Itachi sees potential in Naruto to bring peace to the ninja world and decides to pass on his unique skills like the Sharingan's insights on combat.
One possible plot could be that Itachi, seeing Naruto's potential and his importance for the future of the Hidden Leaf, decides to secretly train him. Itachi might teach Naruto advanced jutsu, especially those related to chakra control and unique Sharingan - inspired techniques. Naruto, under Itachi's tutelage, would grow not only in power but also in his understanding of the ninja world's complex politics and the Uchiha clan's history.
In this fanfiction, Naruto might gain some unique jutsu skills from Itachi. Itachi is extremely powerful, so he could teach Naruto advanced genjutsu or ways to better control his chakra. For example, Naruto might learn how to quickly break free from strong genjutsu attacks, which would be a great advantage in battles against tough opponents.
Well, in a fanfiction where Naruto is trained by Itachi in Sharingan, Naruto would first have to adapt to the new power. Itachi would probably start with the basics of how to activate and control the Sharingan. Since Naruto is used to his own physical and chakra - based training, this would be a challenge. However, with Itachi's guidance, he could master it. Once he does, he could use the Sharingan to analyze his opponents' fighting styles better. For example, he could quickly figure out the weaknesses in an enemy's jutsu and counter them effectively. He could also use the Sharingan's visual prowess to enhance his reaction time during battles.
The relationship between Naruto and Fem Itachi could be a very interesting aspect. They might form a strong bond similar to a master - apprentice relationship in traditional martial arts. Fem Itachi could share her own experiences and wisdom with Naruto, which could help Naruto better understand the world of shinobi, including the Uchiha clan and their secrets.
Naruto may become more calm and composed. Itachi's presence and training methods would likely instill a sense of discipline in Naruto. He'd probably be less impulsive in battles and think more before acting.
One advantage could be a change in his combat strategy. Fem Itachi might teach him more about misdirection and stealth, which are skills that Itachi was known for. This would make Naruto a more unpredictable opponent.
It could be Orochimaru. Since he's always after power and Naruto, with Itachi's training, would become a more appealing target. Orochimaru might see Naruto as a threat to his plans of obtaining all the jutsu in the ninja world.
Naruto would likely become more stealthy. Itachi is known for his stealth and if he trains Naruto, Naruto would pick up some of those skills. He might start to rely less on his brash and straightforward fighting style and incorporate more subtlety.
His understanding of the Uchiha and the darker side of the ninja world would deepen. Itachi would share his experiences, and Naruto would gain a more nuanced view. This might make him more empathetic towards enemies. Also, his combat skills would diversify. He could incorporate Itachi - like precision and speed into his fighting style, becoming a more well - rounded ninja.