Well, it would change a great deal. Firstly, Naruto would have Uchiha blood, which means he might have access to the Sharingan from the start. This would completely change his early struggles as he'd have a powerful dojutsu. His relationship with Sasuke would also be different as they'd be more like cousins. And his place in the village might be more complicated due to the Uchiha's history in Konoha. He could be a target of suspicion or be seen as a potential threat. Also, his training would likely take a different path, perhaps more focused on Uchiha techniques rather than the Rasengan and other Uzumaki - based skills.
Naruto could develop a more brooding personality. With Uchiha blood, he might be more in touch with his emotions, like the typical Uchiha. He'd also be more interested in the Uchiha clan's history and techniques. His power growth would likely be faster as he'd have access to the Sharingan, which can quickly boost one's combat abilities.
One potential antagonist could be Orochimaru. He is always on the lookout for powerful individuals to experiment on or use for his own gain. Mikoto, being an Uchiha, has valuable kekkei genkai that Orochimaru might be interested in. Another could be a group of anti - Uchiha extremists who see Mikoto as a symbol of the Uchiha power they want to destroy.
In this kind of fanfiction, one possible plot could be that Mikoto is in danger from an unknown enemy. Naruto, with his strong sense of justice and his powerful ninja skills, somehow discovers her plight. Maybe he stumbles upon a battle where Mikoto is outnumbered and on the verge of defeat. He then jumps into the fray, using his Rasengan or other signature moves to fend off the attackers and save her.
Some fanfictions focus on the idea of Naruto being adopted by the Uchiha family. In this scenario, Mikoto becomes his mother figure. They might have heart - to - heart conversations about Naruto's loneliness and Mikoto's concerns for her family. Also, there could be a plot where Naruto's positive influence on Sasuke starts earlier because of his relationship with Mikoto, and this changes the whole dynamic between Naruto and Sasuke in a positive way.
One possible plot could be that Naruto travels back in time and meets Mikoto Uchiha. He might try to prevent the Uchiha massacre. Since Naruto has knowledge of future events, he could use this to his advantage. He could also form an unlikely alliance with Mikoto, who was an important figure in the Uchiha clan. This could lead to a whole new timeline where the Uchiha clan doesn't face destruction and Sasuke has a different upbringing.
Writers often portray their relationship as a mentor - mentee type. Mikoto, being an experienced Uchiha, can teach Naruto things about the ninja world and the Uchiha clan. For example, she could show him how to control chakra more effectively using Uchiha - style techniques.
There's also 'Mikoto's Legacy in Naruto's World'. In this fanfic, it explores how Mikoto's past actions and her Uchiha heritage play a role in Naruto's journey. It has some really interesting plot twists that keep you hooked.
Another theme is the Uchiha clan. Fanfics often focus on Mikoto's role within the clan. This can include her dealing with the clan's politics, traditions, and the dark secrets that the Uchiha clan held. For example, how she navigated the growing tensions within the clan before the Uchiha massacre.
Yes, there are quite a few. You can check out some popular fanfiction websites like FanFiction.net or Archive of Our Own. Some of these fanfictions might offer unique takes on Naruto being the son of Mikoto and Fugaku, exploring different character relationships and plot developments.