In a Naruto fanfic where Mikoto is brainwashed, she could be made to do things against her normal nature. For example, she might be forced to fight against her friends or family. Maybe she'll be used as a tool by the villains in the fanfic's plot to gain some advantage over the other characters. It really depends on the creativity of the fanfic writer.
If Mikoto is brainwashed in a Naruto fanfic, it would be a really interesting plot twist. First, it would change the power dynamics in the story. Since Mikoto was a powerful Uchiha, her being under someone else's control could shift the balance. Second, it could be used to explore themes of mind control and free will. The author could show how Mikoto struggles against the brainwashing, or how the other characters react to her new state. It could also create some really emotional scenes, like when her loved ones try to reach out to the 'real' Mikoto inside.
Well, Naruto would likely gain a different perspective on the Uchiha. Mikoto could share stories about Itachi and Sasuke when they were younger. This would make Naruto understand Sasuke on a deeper level. For example, he might realize why Sasuke is so driven by revenge and be better equipped to handle their relationship.
Well, in such a fanfic, Naruto might turn against his friends. He could be made to use his power for Danzo's often shady purposes. For example, he might be forced to target those Danzo sees as threats to Konoha in a more brutal way than he normally would. His relationships would be severely damaged as his friends would be confused and likely try to stop him, not realizing he's been brainwashed at first.
Brainwashed Mikoto can have a huge impact on the plot. She could be used to start conflicts. For example, if she attacks other characters without reason due to the brainwashing, it would lead to battles and new rivalries.
Well, they could become rivals. Since Naruto is always striving to be the best and Mikoto, being from the Uchiha clan, would also be highly competitive. They might compete in various ninja tasks and exams, constantly pushing each other to improve.
One possible plot could be that Mikoto somehow survived and she takes Naruto under her wing. She trains him secretly, using her Uchiha knowledge to make him stronger. This could lead to Naruto having a unique set of skills that no one else has.
The plot could revolve around a mystery in the village that only Kushina, Mikoto and Naruto can solve. Maybe there are strange disappearances that are related to an ancient power that was once sealed by the Uzumaki clan and has some connection to the Uchiha. Kushina uses her knowledge of the Uzumaki history, Mikoto her understanding of the Uchiha lore, and Naruto his unique perspective as the Jinchuriki of the Nine - Tails. They have to overcome their differences and work together to save the village from this hidden threat. Along the way, they develop a deeper bond as they face various challenges.
A possible plot is that Mikoto stumbles upon baby Naruto in the forest. She takes him back to the Uchiha compound. There, she raises him as one of their own, much to the confusion of some Uchiha members. As Naruto grows, he starts to show unique abilities that are a combination of his Uzumaki heritage and the influence of the Uchiha environment.
Well, it could be about Mikoto seeing Naruto's lonely situation and deciding to take him in. Maybe she'd teach him some Uchiha techniques and help him grow stronger. She could also introduce him to Sasuke as a brother figure, changing the whole dynamic between Naruto and Sasuke in the Naruto world.
Well, perhaps in this fanfic, Naruto being raised by Mikoto means he has a more stable and loving upbringing. He could be friends with Sasuke from a very young age, and they might grow up like brothers. Naruto would also be exposed to the Uchiha's rich history and culture, which could shape his understanding of the ninja world and his own place in it. He might even get to know some secrets of the Uchiha clan that no one else outside the clan knows.
In this fanfiction, perhaps Mikoto could teach Naruto some unique Uchiha techniques. Since she's from the Uchiha clan, she might have insights into fire - style jutsu that could help Naruto diversify his skills.