In some fanfictions, it could be through a special jutsu or ritual. Maybe Itachi, before his death, transferred his Sharingan to Naruto in a unique way, perhaps using a forbidden technique that was known only to a few in the Uchiha clan.
One possible fanfiction could be that Itachi, on his deathbed, decides to transfer his Sharingan to Naruto. He sees in Naruto the potential to change the Uchiha's fate and the ninja world. Naruto, with the Sharingan, gains new abilities like enhanced perception and the ability to copy some jutsus more easily. He uses this new power to better understand the Uchiha and bridge the gap between them and the rest of the village.
I really liked 'Itachi's Hidden Truths'. In this fanfic, the author gives a different perspective on Itachi's actions. It shows how his Sharingan abilities were not just for combat but also for protecting those he cared about in his own, often misunderstood, way.
One possible scenario in such a fanfic could be that Itachi, seeing Naruto's potential and his pure heart, decides to entrust Naruto with his Sharingan. This could potentially give Naruto new abilities and a deeper understanding of the Uchiha clan's power. It might also create a unique bond between Naruto and the memory of Itachi, leading to new storylines where Naruto uses the Sharingan's powers in unexpected ways.
A good Naruto Sharingan Itachi fanfic should have a deep understanding of Itachi's character. His motives, like protecting Konoha at all costs, should be well - explored. Also, the power of the Sharingan should be accurately depicted, for example, showing how he could use genjutsu with it.
They could develop a mentor - mentee relationship. Itachi uses his knowledge of the Sharingan to teach Naruto new combat techniques. As they train together, they bond over their shared experiences of loss and their desire to protect the people they care about. Naruto might also help Itachi come to terms with his past actions and find some peace within himself.
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.
Itachi is such an interesting character in the Naruto series. His Sharingan abilities are cool and powerful. In fanfiction, writers can expand on his story, his relationships, and his inner thoughts. For example, they can explore his relationship with Sasuke in new ways or show how he developed his Sharingan skills. Also, the idea of Itachi as a tragic hero makes people want to read more about him in fanfiction.
A simple plot could be that Itachi entrusts Naruto with his Sharingan because he believes Naruto can use it to bring peace to the ninja world. Naruto, being the kind - hearted person he is, accepts the responsibility. He starts training with Kakashi to understand and master the Sharingan's powers. With the Sharingan, Naruto can anticipate his opponents' moves better and uses this advantage in battles against powerful enemies like Pain.