In a Naruto joins the Uchiha clan fanfiction, he could be adopted by an Uchiha. For example, if Sasuke had a change of heart early on and decided to bring Naruto into the clan. Naruto would then be exposed to the Uchiha's dark past and their thirst for revenge. He could use his own positive attitude to try and change the clan's perspective. And he'd surely have to train hard to keep up with the Uchiha's high standards in combat and ninja skills.
If Naruto joins the Uchiha clan, his character would develop in several ways. He would have to adapt to the clan's hierarchical structure. This could make him more respectful of traditions. His relationship with Sasuke would take on a whole new dimension. They could become more like brothers within the clan, and Naruto would have a stronger sense of family. Also, his understanding of power and responsibility would grow as he learns about the Uchiha's power - hungry past and how it led to their downfall.
For other Uchiha clan members, they could start to view Naruto in different ways. At first, they might be skeptical of him, but as he shows his strength and loyalty to the clan, they could come to accept him. This could also lead to Naruto influencing the Uchiha clan's traditional views and values, causing some of the younger members to think more openly about the clan's future and its relationship with the outside world.
In many fanfics, Naruto might save the Uchiha clan by preventing the massacre. He could use his influence and friendship to change Itachi's mind. For example, if Naruto had known about the threat to the Uchiha clan earlier, he might have been able to talk to the village elders and find a peaceful solution. He could also have protected the Uchiha clan from outside threats that might have led to their downfall.
Power and its consequences is another theme. The Uchiha are known for their powerful Sharingan. Fanfics often explore what happens when an Uchiha gains too much power or misuses it. They also look at how the clan's power affects their relationships with other clans in the Naruto universe. In addition, the theme of family loyalty is prevalent. The Uchiha clan has a strong sense of family, and fanfics often depict characters' loyalty to their clan members and how they navigate when that loyalty is tested. This can be seen in stories where an Uchiha has to choose between the greater good and the well - being of their clan.
If Naruto saved the Uchiha clan, the story of the Hidden Leaf Village would be rewritten. The history of the Uchiha's massacre would no longer be a dark stain on the village's past. The Uchiha would contribute their unique skills and abilities to the village's development. For example, their Sharingan abilities could be used for better security or in battles against common enemies. There would also be a change in the relationships between characters. People who were once enemies of the Uchiha might have to learn to work with them.
One possible plotline could be Naruto being adopted into the Uchiha clan early on. He might then learn the unique Uchiha jutsus and secrets at a young age. This could lead to him having a different relationship with Sasuke, perhaps as a brother - like figure within the clan.
One possible motive could be mind control. Maybe an enemy used a powerful genjutsu on Naruto, forcing him to commit this heinous act against the Uchiha clan.
A plotline could involve Naruto finding a hidden power within the Uchiha clan that was overlooked. He uses this power to unite the clan and make them strong enough to resist any threats. Maybe this power is related to an ancient Uchiha technique that Naruto helps to rediscover. He then uses his charisma and leadership skills to convince the Uchiha to work with the village instead of against it.
Well, in such a fanfic, Naruto might have the Sharingan from birth. He could be trained in Uchiha - style jutsu right from the start. His personality might be influenced by the Uchiha clan's pride and determination. Also, his relationships with other characters like Sasuke would be very different, as they would be clan - mates instead of rivals in the traditional sense.