Their relationships would become very complicated. For example, romantic relationships would be difficult. Their partner would age while they stay the same. It could lead to a lot of heartbreak and the OC might have to distance themselves to avoid seeing their loved one wither away.
Friendships would also be affected. The OC would see their friends grow old and die. They might make new friends over time, but the cycle of loss would be a constant in their life. They could also become a sort of mentor figure to younger generations, but always with the knowledge that they would outlive those they are mentoring.
His relationship with Sasuke would be different. Instead of the rivalry born out of their time in Konoha, it could be more of a friendly competition between two powerful clans. Naruto, being Uzumaki - raised, would have a different perspective on power and friendship.
His relationship with Sasuke would be different. Without the shared experience of being outcasts in the village, they might not have the same initial bond. Naruto would have a stronger support system from his Uzumaki family, so he might not be as desperate for Sasuke's friendship in the same way.
His relationship with Sasuke would likely be very different. Sasuke might be more in awe of Naruto, but also feel a greater sense of distance. They would no longer be just rivals, but there could be a new power dynamic where Naruto is in a much higher position.
His relationships would change a great deal. With Sasuke, there might be a new level of respect. Sasuke would see Naruto in a whole new light, not just as a rival but as someone truly powerful. His friends like Sakura and Kakashi would be more in awe of him. They might feel a bit of distance at first, but Naruto would try to bridge that gap. His enemies would be either terrified or would try to use his new status to their advantage.
If Naruto became a succubus in fanfiction, his relationships would change significantly. His friendship with Sasuke, for instance, would face a new dynamic. Sasuke, who is often focused on power, might view Naruto's new form as either a threat or a potential source of power. Naruto's relationship with Sakura could also be affected. Sakura might initially be shocked and unsure how to interact with him. She could be worried about Naruto's new nature and how it could impact his well - being. And Naruto's relationship with Kakashi would require some adjustment. Kakashi would need to understand Naruto's new abilities and how to help him control them while still maintaining their mentor - mentee bond.
Romantic relationships would also be affected. If Yusei had a love interest, she or he would be heartbroken and confused. They might try to reach out to Yusei and bring him back from the dark side. But Yusei, as a Dark Signer, might push them away, believing that his new path is one he has to walk alone. His relationships with his mentors or older figures in his life would also turn sour, as they would see him as having strayed from the right path.
If Naruto became a dragon bijuu in fanfiction, his relationship with his friends would face a big transformation. His friends would need to get used to his new appearance and powers. For instance, they might be scared at first when they see him as a dragon. But as time goes on, they would realize that Naruto is still the same person inside. However, his enemies would see him as a more dangerous target. And his relationship with the other bijuu could also change. He might be seen as an equal or even a leader among them, which would change the power dynamics in the bijuu world.
When Boruto goes back in time, say to the era of the Third Hokage. His relationship with the village elders and the teachers at the ninja academy would be completely new. He would be seen as an oddity since he has knowledge and skills that are not from that time. He might form unexpected friendships with some of the young ninjas of that era. His relationship with his own family members in the past, like his grandparents, would also be very interesting. He could learn a lot about his family's history and values from them, which would change how he views his family in his own time.
If he's reborn as a vampire, his relationships would be drastically different. He might form new alliances with some vampires while being in conflict with others. For example, he could befriend Carlisle Cullen due to his kind nature, but be at odds with the Volturi. As for relationships with humans, he would have to hide his true nature, which could lead to some complex and strained relationships. He might be drawn to Bella Swan because of her connection to the vampire world, but also have to keep his distance to protect her.
If Naruto became a human puppet, his relationships would be drastically different. His friends like Sakura and Sasuke would likely be shocked and saddened. Sakura, who has always seen Naruto as a determined and warm - hearted friend, would have a hard time accepting this new, mechanical version of him. Sasuke, on the other hand, might view Naruto as a failed experiment or a lost cause. Naruto's relationship with his teacher, Kakashi, would also change. Kakashi would no longer be able to train Naruto in the same way as before. His bond with the village of Konoha would be strained. The villagers who once looked up to him as a hero might be scared or disgusted by his new form.