One possible plot twist could be that Naruto struggles to control the Sharingan at first. Since he's not from the Uchiha clan, the Sharingan's powers might act differently in him. For example, instead of the normal abilities like predicting movements, it might give him visions related to the Uchiha's past traumas. This could lead to Naruto having to deal with not only the power of the Sharingan but also the emotional baggage that comes with it.
One possible plot twist could be that Naruto's new Mangekyou Sharingan gives him the ability to access a new form of Sage Mode. Since the Sharingan has unique powers and Sage Mode is Naruto's own power, their combination might create something unexpected. For example, he could use the Sharingan to better target his Sage chakra, making his attacks more precise and powerful.
One possible plot twist could be that Naruto's Sharingan has unique abilities not seen in the regular Uchiha Sharingan. Maybe it can combine with his Sage Mode in unexpected ways, like seeing chakra flows more clearly even in Sage Mode, enhancing his combat skills.
One possible plot twist could be that Naruto Namikaze, having the Sharingan, discovers a hidden connection between the Uzumaki and Uchiha clans that was long forgotten. This connection might give him unique powers or abilities that no one expected.
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.
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.
A plot twist could be that Naruto receives the Mangekyou Sharingan from Sasuke in a self - sacrificing moment. Sasuke, realizing the true potential of Naruto's power combined with the Sharingan, decides to transfer his Mangekyou Sharingan to Naruto. This would create a whole new dynamic in their relationship. Naruto would then have to master the abilities of the Sharingan quickly to face an impending and powerful threat to the Hidden Leaf Village.
Well, it changes a lot. For one, Naruto's power level gets a significant boost. Instead of relying solely on his Uzumaki chakra and Sage Mode, he now has the Sharingan's abilities like predicting movements and using genjutsu. This can make battles he's in much more complex and unpredictable.
Another plot twist could be that Naruto getting the Sharingan is part of a much larger conspiracy. The Akatsuki might be behind it, trying to create a super - powerful being that they can control. So Naruto has to figure out who's behind this while also dealing with the new power. He might find that there are some hidden motives among his own allies as well, which would really shake up the story.
One possible plot twist could be that Naruto gains the Mangekyou Sharingan in a moment of extreme emotional turmoil, like seeing Sasuke in a life - threatening situation. This new power might make him an outcast in Konoha at first, as the Sharingan is a symbol of the Uchiha. Another twist could be that the Mangekyou Sharingan has some unforeseen side effects on Naruto's chakra system, making it difficult for him to control his normal jutsu. It could also lead to a power struggle within the village as some might fear Naruto's new - found power.
One interesting storyline could be Naruto using the Sharingan to enhance his combat skills in a new and unexpected way. For example, he might combine his Rasengan with Sharingan - powered genjutsu to create a more powerful and deceptive attack.