Itachi could train Naruto to better understand the nature of chakra. He might show Naruto how to sense and manipulate chakra in ways he hadn't considered before. For example, Itachi could teach Naruto how to infuse his Rasengan with different elemental chakra more effectively. This would give Naruto an edge in combat against stronger opponents. Also, Itachi could train Naruto in stealth and infiltration techniques, skills that Naruto has not really focused on before.
In the fanfiction, Itachi might train Naruto to be a better leader. Naruto is already seen as a hero in the village, but Itachi could teach him how to make tough decisions and lead by example. The training could take place in a hidden location where Naruto has to endure physical and mental challenges. Itachi could use his own experiences as an Uchiha and a former member of Akatsuki to teach Naruto about the darker side of the shinobi world and how to avoid making the same mistakes that led to so much destruction.
One possible fanfiction could involve Itachi returning from the dead in some way. He decides to train Naruto to help him master new skills. Itachi might teach Naruto some of the more advanced Uchiha techniques, like advanced fire - style jutsu or the sharingan - related skills he has. Naruto, with his own vast chakra reserves and unique abilities, would then combine these new teachings with his own Rasengan - based attacks. This could lead to some really cool battle scenes in the fanfiction where Naruto surprises his enemies with new moves.
One possible plot twist could be that Naruto, while modeled after Itachi, has to face off against Sasuke who mistakes him for Itachi at first. This would create a really tense and emotional situation as Sasuke's hatred for Itachi might be misdirected towards Naruto.
In this fanfiction, Naruto might gain some unique jutsu skills from Itachi. Itachi is a very powerful shinobi, so he could teach Naruto advanced techniques of chakra control and some secret Uchiha clan jutsu.
A common plot element is that Itachi's training helps Naruto gain new powers or improve existing ones. This makes Naruto more appealing to Hinata. Another element could be that during the training, Naruto has some self - discovery moments related to his feelings for Hinata. For example, he might realize how much he wants to protect her.
Perhaps the fanfiction could be about Naruto training Percy in stealth. Percy, being a demigod, often charges into battle head - on. Naruto, on the other hand, is a master of stealth. He could teach Percy how to move quietly and undetected. This would be a great advantage for Percy when he has to infiltrate a monster's lair or spy on the enemy. The story could show Percy struggling at first but gradually getting better with Naruto's guidance.
Another ability Naruto could develop is enhanced stealth. Itachi is known for his stealth and ability to move undetected. During the three - year training, Itachi could teach Naruto how to move more quietly, hide his chakra signature better, and approach opponents without being noticed. This would give Naruto an edge in combat, especially when facing more powerful opponents where a surprise attack could be crucial.
There could be a focus on Naruto learning new forms of the Rasengan. Hokage Naruto, with his vast experience, could teach Naruto different ways to infuse the Rasengan with other elements more easily. Maybe Naruto would learn how to quickly switch between a Fire - Rasengan and a Wind - Rasengan during combat.
One possible plotline could be Itachi teaching Naruto advanced jutsu techniques. For example, Itachi might show Naruto how to use his chakra more efficiently in combat, which could give Naruto an edge against stronger opponents. Another plotline could involve Itachi sharing some of the secrets of the Uchiha clan with Naruto, like the true nature of the Sharingan. This could lead to Naruto developing new strategies that combine his own abilities with what he's learned from Itachi.
One possible plot could be that they meet in secret locations like an abandoned training ground. They start sharing their deepest secrets and feelings. As they date secretly, they have to be careful not to be seen by Sasuke, who has his own complex relationship with Itachi. Their relationship could also be a way for Itachi to redeem himself in a different way, by being with Naruto who represents hope in the Naruto world.
One possibility is that Itachi finds Naruto in a vulnerable state and decides to take him in as a pet. Naruto might initially resist but then come to understand Itachi's motives. It could be a story of Naruto learning from Itachi's skills and wisdom while being in this unique 'pet' relationship.