Mikoto could also set up training scenarios for Naruto to experience what it's like to face an opponent with the Sharingan. This hands - on approach would make Naruto more aware of the Sharingan's abilities such as predicting movements, seeing through illusions, and copying techniques. Through these experiences, Naruto would be better equipped to counter the Sharingan in his future battles and maybe even find ways to use its principles in his own unique fighting style.
Mikoto could influence Naruto's understanding of the Sharingan by sharing her own experiences with it. As an Uchiha, she has first - hand knowledge of the power and the curse that comes with it. She could tell Naruto about the different levels of the Sharingan and how to unlock them. This would give Naruto a new perspective on the power and how to use it effectively.
One way this could occur in the fanfiction is if there was some sort of genetic manipulation. Maybe a rogue ninja or a mad scientist found a way to combine Uchiha genes with Naruto's. Mikoto, being an Uchiha, had the Sharingan, and through this unethical genetic process, Naruto ended up with the Sharingan. This would also open up a whole new set of abilities and challenges for Naruto as he has to learn to control this new power which is very different from his normal chakra - based powers.
Another plot could revolve around a time - travel scenario. Naruto gets sent back in time and meets a young Mikoto. They form an unlikely friendship. Mikoto, seeing Naruto's strange abilities and determination, decides to help him understand the Sharingan better. In the process, Naruto ends up changing the future of the Uchiha clan in some way, preventing the tragedy that was to befall them.
Mikoto could be developed as a more powerful figure. Since she has the Sharingan, she could be shown exploring and mastering abilities that were not fully explored in the original series. For example, she might discover a new type of genjutsu unique to her Sharingan that she then uses to protect the Uchiha clan.
In fanfiction, Naruto could get the Sharingan through a blood - related connection that is revealed later. For example, it could be discovered that he has some distant Uchiha ancestry that gets activated somehow. Maybe a powerful enemy's attack awakens this dormant Uchiha blood in him, and as a result, he develops the Sharingan. It could also be that a powerful sage or a new character uses their own unique powers to bestow the Sharingan upon Naruto for a specific purpose.
One way could be through a kekkei genkai transfer jutsu. If a powerful ninja, perhaps an old hermit with knowledge of ancient jutsus, decides to transfer Sasuke's Sharingan to Naruto for the greater good of the village. This jutsu might be risky but in the world of fanfiction, anything is possible.
Well, it could be that Mikoto is trapped in a dangerous situation like a collapsing building or a genjutsu. Naruto, with his strong will and powerful chakra, breaks the genjutsu or rescues her from the rubble. He might sense her distress using his Sage Mode or his connection to the Nine - Tails' chakra and rush to her aid.
Well, if Naruto is the father of Mikoto in the fanfiction, it could bring a whole new dynamic. Naruto is known for his strong will and his ability to make friends and change people's minds. As Mikoto's father, he might instill in her the same values. Also, considering Naruto's connection to the Nine - Tails, there could be some interesting plot twists. For example, Mikoto might have some sort of special ability related to the Nine - Tails or Naruto could have passed on some of his chakra to her, which would give her an edge in battles.
In a fanfiction, Naruto might obtain the Rinnegan and Sharingan through a unique encounter. For example, he could stumble upon a dying Uchiha who transfers his Sharingan to Naruto in a moment of desperation. As for the Rinnegan, it could be related to his connection with the Sage of Six Paths. Perhaps the Sage's spirit, seeing the great need in the ninja world, bestows the Rinnegan upon Naruto. It could also be a result of some sort of genetic experimentation gone wrong but in a way that gives him these powerful eyes instead of harming him.
In some fan theories, it could be due to a unique chakra interaction. Maybe the Kyuubi's powerful chakra somehow mutates Naruto's own ocular abilities and triggers the emergence of the Sharingan. But this is just a wild fanfiction idea.
He would gain new visual abilities. Naruto could now use the Sharingan's powers like predicting movements, copying jutsus more easily. But it might also come with some drawbacks. For example, the Sharingan consumes a lot of chakra, so Naruto would have to manage his energy better.