After Stuart's transformation, if he turned into a large animal like a deer, his relationship with his mouse family would be very different. He'd no longer fit in their small mouse - sized world. He might feel a bit lonely at first, missing the closeness he had with his family. However, he could form a bond with other deer herds, learning their social hierarchies and ways of communicating, and gradually build a new family - like relationship with them.
One idea could be Stuart transforming into a bird. He could use his newfound ability to fly and explore the world from above, encountering other bird species and having adventures in the sky. Another could be him turning into a fish. He'd swim in the pond or aquarium, make friends with other fish, and discover the underwater world's secrets.
His relationship with Sasuke would be completely different. Instead of being rivals, Sasuke might see Naruto as a sort of replacement for Itachi, which could lead to a very complex dynamic. Maybe Sasuke would be drawn to Naruto in a strange way, not sure if he should hate or befriend him.
If Naruto were not human, his relationships would likely be very different. For example, his relationship with Sasuke might be more strained. Sasuke, who is very focused on power and revenge, might see Naruto as a greater threat if he's not human. He could view Naruto's non - human abilities as something to envy or fear. With Sakura, she might be more hesitant around Naruto. Instead of her initial crush, she could be more cautious, not knowing what Naruto is truly capable of.
With Sakura, she might be initially afraid of Naruto's demon form. But as she realizes that Naruto is still the same person inside, she could become more protective of him and help him control his powers. Their friendship could deepen in a different way compared to the original story.
Suppose Percy turns into a horse. His close friends might feel a sense of responsibility to protect him, especially if he's in a dangerous area. He could form a bond with other horses, and this might introduce new characters into the story. His relationship with his human family might become more complex as they struggle to understand his new state and how to interact with him as a horse.
Well, some characters might become closer. If they find that a fanfiction portrays their relationship in a positive and deeper way than the original, they could develop a stronger bond. For instance, two characters who were just friends in the original might see a potential for more in the fanfiction and start to explore that in their own relationship.
Well, some relationships might become stronger. For example, Thor and Rocket might bond more over their shared experiences in Endgame. They could start to rely on each other even more in future battles.
His relationship with Ladybug would be severely strained. Since he's akumatized, Ladybug would see him as an enemy she has to defeat, which would be a huge shift from their usual partnership. With his father, Gabriel might initially be shocked but then could see it as an opportunity to control Adrien's new powers for his own evil plans. And his friends like Nino would be very confused and scared, not understanding why Adrien has turned into this akumatized being and would try to find a way to bring him back to normal.
In a fanfiction where Issei turns into a dragon, his relationships would be in flux. His relationship with his mentors or those he looks up to might change as they now see him as a different kind of being. They might treat him with more caution or more respect depending on how they view dragons. His friendships with his peers would also be altered. Some might see him as a weapon to be used in their battles or struggles, while others would see him as a friend in need of support. Romantically, if he had feelings for someone, that person would have to deal with the fact that Issei is no longer fully human. There could be jealousy from others who might want to be with the powerful dragon - Issei, or there could be newfound admiration from those who previously overlooked him.
His relationship with Kagome would change significantly. Kagome might see Inuyasha in a new light, perhaps more as a sister - like figure at first, but then as she gets used to the new form, there could be a shift in their romantic undertones. With Miroku, Miroku would be more respectful in a different way. He might be less likely to tease Inuyasha in the same way he did before. Sesshomaru, on the other hand, might initially be disgusted or confused by his half - brother's new form, but it could also lead to some interesting developments in their rivalry as Sesshomaru tries to figure out if this new Inuyasha is still a worthy opponent.