The plot implications are quite significant. For starters, it could change Naruto's relationships with his friends. Some might be jealous or afraid of his new power. Also, it could attract the attention of dangerous enemies. Those who were after Shisui or the Sharingan might target Naruto. This would put Naruto in a whole new set of dangerous situations and force him to grow and adapt in different ways. Additionally, it might also change the way Naruto approaches his ninja training, as he has to learn to master the Sharingan's abilities.
In the fanfiction, if Naruto gets Sharingan from Shisui, there are several plot implications. It might lead to a shift in the power balance in the ninja world. With Naruto's existing strength and the addition of the Sharingan, other villages might view Konoha as an even greater threat. This could spark new conflicts or alliances. Also, within Konoha, there could be political unrest. The elders might be worried about Naruto's new power and try to control or suppress him. And Naruto himself would have to deal with the internal struggle of being a Jinchuriki and now having an Uchiha power, which could be a major part of the plot's development.
One plot implication could be that Naruto becomes an outcast among some in the village who fear the power of the Sharingan. This would create internal conflict within Konoha. Another is that Naruto might be targeted by enemies who want to either steal the Sharingan or kill him to prevent him from becoming too powerful. Also, it could change his relationship with Sasuke, as they both now share a connection to the Sharingan.
One possible plot implication is that it could create a rift between Naruto and some of the shinobi in the village. Since the Sharingan is an Uchiha - specific power, some might be suspicious of Naruto having it. Another is that it could lead to Naruto being targeted by those who want the Sharingan for themselves.
In this fanfiction, a really interesting plot twist could be that the training by Shisui actually awakens a dormant power within Naruto that has nothing to do with the Sharingan at first glance. As Naruto delves deeper into the Sharingan training, he starts to notice connections between this new power and the Sharingan. Maybe it's a power related to the Sage of Six Paths that gets activated in a unique way due to the Sharingan training. Also, the relationship between Naruto and Shisui could take an unexpected turn. Instead of just a teacher - student relationship, they could become something like comrades with a shared mission that is revealed during the training process.
One potential implication is that Naruto's fighting style would change drastically. He would have to learn how to use the Sharingan's abilities like predicting movements and copying jutsus. This could make him an even more formidable opponent.
One potential implication is that Naruto would gain enhanced visual abilities. The Sharingan can copy jutsu and see through illusions, so Naruto would be even more powerful in combat. For example, he could quickly learn new enemy techniques during battles.
In fanfiction, Shisui's Sharingan often has some unique abilities. It's usually depicted as having powerful genjutsu - related powers. For example, it might be able to cast illusions on multiple opponents at once with greater ease compared to a normal Sharingan. His Sharingan can also potentially be used to transfer memories in more creative ways in fan stories, like not just the basic memory transfer we saw in the original Naruto series but perhaps more complex emotional and skill - based memories.
One possible fanfiction could be that Naruto is on a mission and encounters a powerful Uchiha who, instead of killing him, transfers his Sharingan to Naruto for some mysterious reason. Naruto then has to learn to control this new power while still maintaining his own unique ninja style.
In this fanfiction, a likely plot development could be that Naruto starts to experience strange visions or memories from Shisui's brother due to the Sharingan. This causes him to go on a journey to discover the secrets behind these visions. Also, the Leaf Village elders might become suspicious of Naruto's new power and try to keep an eye on him, which creates internal conflicts within the village.
In some fanfictions, Shisui's Sharingan has a different color or pattern. This is a simple but effective way to make it stand out. For example, it could be a deeper red or have an extra swirl in the pattern.
If Naruto had the Sharingan in fanfiction, it would likely lead to some interesting power - up scenarios. He could combine the power of the Sharingan with his own massive chakra reserves. This might make him an even more formidable opponent. His training would also take a new turn as he'd have to learn to control and master the Sharingan's abilities, like the different levels of the Sharingan and their unique powers.