In some fanfictions, it could be due to a special jutsu gone wrong. Maybe a jutsu that Kakashi was using to transfer some of his chakra to Naruto for a mission accidentally transferred his Sharingan power as well.
Well, Naruto might gain new abilities. He could potentially use the Sharingan's powers like predicting movements better in combat. It would be a huge boost to his already formidable skills.
One great fanfiction could be about Kakashi using his Sharingan to train Naruto in a special jutsu. Maybe he shows Naruto how to better perceive an opponent's moves by using the Sharingan's ability to analyze. This could lead to Naruto developing a new and powerful technique that combines his own chakra control with the insights from the Sharingan.
The consequences could be far - reaching in the fanfiction. Naruto's relationship with Kakashi might change. There could be a deeper sense of respect and a new kind of bond formed because of this transfer. In terms of power, Naruto could unlock new jutsus or abilities that are related to the Sharingan. He might be able to combine his existing Rasengan techniques with the Sharingan - enhanced perception. This could make him an even more formidable opponent. However, it could also put a strain on his body. The Sharingan is known to consume a lot of chakra, and Naruto's body might need to adapt to this new power drain. If he overuses it, it could lead to exhaustion or even long - term damage.
The story might progress as Naruto struggles to control the Sharingan at first. He may have some internal conflict as he tries to incorporate this new power into his existing set of skills. As he gets better at using it, he could start to change the power structure in the ninja world. His relationships with his friends and allies could also be affected. For instance, Sakura might be more worried about him as the Sharingan could put a strain on his body. Naruto could also use the Sharingan to uncover secrets about his parents or the history of the ninja clans that were previously unknown.
Well, it might be that there's a powerful enemy who can only be defeated if Naruto has the Sharingan. Sasuke, realizing this, decides to transfer his Sharingan to Naruto. In the fanfiction, Naruto would then have to deal with the new power. He might struggle at first to control it as it's not his natural ability. But as time goes on, he could use it to better understand Sasuke's perspective and strengthen their bond even more. He could also use it in battle, perhaps seeing his opponents' moves more clearly and countering them more effectively.
Well, if Naruto gets Shisui's Sharingan in a fanfiction, he could gain some really cool abilities. The Sharingan has powers like enhanced perception and the ability to copy jutsu. Naruto already has his own powerful chakra and skills, so with the Sharingan, he might become an even more formidable ninja. He could potentially use the Sharingan's genjutsu capabilities to his advantage in battles, maybe even use it to break through tough enemy defenses more easily.
One interesting fanfic could be where Kakashi uses his Sharingan in a unique way to train Naruto. Maybe he shows Naruto how to better analyze his opponents' moves just by using the Sharingan's ability to copy and predict. For example, Kakashi could create a special training ground where Naruto has to face multiple clones of himself that mimic the fighting styles of different enemies. And the Sharingan plays a crucial role in Naruto understanding the patterns of these clones.
One great 'Naruto Kakashi's Sharingan' fanfic could be 'The Legacy of the Sharingan'. It delves deep into how Kakashi's Sharingan not only affects his combat abilities but also his relationships with other characters like Naruto. It might show how he passes on some of his knowledge related to the Sharingan to Naruto.