In the fanfiction world, it could be due to a deep emotional bond between Naruto and Sasuke. Their connection could be so strong that in a moment of extreme danger or a spiritual awakening, Sasuke's Sharingan essence is transferred to Naruto. For example, if Sasuke was on the verge of death and his chakra merged with Naruto's in a desperate attempt to save Naruto, the Sharingan could be part of that transfer. This would also add a whole new layer to their relationship and Naruto's character development as he would have to learn to control this new power.
One way could be through a powerful jutsu gone wrong. Maybe a jutsu that was meant to transfer Itachi's memories to Naruto accidentally transferred his Sharingan as well. In the world of fanfiction, there are often many creative and out - of - the - box explanations.
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.
In a fanfiction where Naruto kills Sasuke and obtains the Sharingan, it would be a game - changer for the story. Naruto would gain new abilities like enhanced visual perception and the potential to use some of the Uchiha's signature jutsu. However, this would also create a lot of internal conflict within Naruto. His ninja way has always been about saving his friends, not killing them. So, this act would make him question his own identity and values. Moreover, the political situation in the ninja world would be in chaos. The Uchiha clan's power being transferred to Naruto, an outsider in terms of the Uchiha, would be a controversial matter that could spark new rivalries and alliances.
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.
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.
Well, he could gain some amazing new abilities. The Sharingan is known for its copying abilities, so Naruto might be able to copy jutsus more easily. He could also potentially gain some of the Uchiha clan's unique powers related to genjutsu. This would change his combat style significantly, making him even more unpredictable to his enemies.
In fanfiction, if Naruto got the Sharingan from Madara, it would completely change his power dynamic. He would gain the abilities of the Sharingan like enhanced perception, the ability to copy jutsu more easily, and perhaps even access to some of Madara's unique Sharingan - based techniques. This would make him an even more formidable opponent and could potentially change the entire plot of the Naruto universe within the fanfiction world.
His powers would change a great deal. Naruto is known for his brute strength and his ability to never give up. The Sharingan would add a whole new layer of finesse to his fighting style. He could use the Sharingan's genjutsu capabilities to trap his enemies in illusions before hitting them with a powerful chakra - infused punch. Also, he could use it to analyze his opponents' weaknesses more quickly, allowing him to adapt his fighting strategy on the fly.
One possibility is that Naruto would gain incredible new abilities. Shisui's Sharingan had unique powers like Kotoamatsukami. With it, Naruto might be able to influence others in a more subtle way. He could use it in battles to deceive opponents or even resolve conflicts without direct combat. For example, he could use it to make enemies see illusions of peace and lay down their weapons.