Well, it depends on the nature of the transformation. If it was a sudden and complete change, his relationships would be shattered instantly. But if it was a gradual process, some people might try to help him at first. However, as the transformation progressed and he became more and more like a monster, they would probably give up out of fear. His loved ones would struggle between their love for the man he used to be and their fear of the monster he was becoming.
If he had a family, they would be terrified. His partner might leave him, not being able to handle the new, monstrous form. His children would be scared and confused. Even his colleagues at work would shun him. The transformation would isolate him from the normal social interactions he used to have.
His transformation into a dragon might initially strain his relationships. His friends may be scared or not know how to deal with him in this new form. However, over time, they could learn to accept and even rely on his new dragon powers. For example, if he has enhanced strength or the ability to fly, he could help his friends in new ways.
His relationship with Sasuke would be greatly affected. Sasuke might initially be confused or even a bit jealous of Naruto's new form and powers. But as they face challenges together, they would learn to work with Naruto's Pokemon - like abilities. For example, if Naruto could fly as a certain Pokemon, he could help Sasuke in battles in new ways.
The transformation can cause destruction. For example, the newly formed monster might thrash about, knocking down trees or buildings. It can also spread a sense of unease that affects the wildlife, making them flee or act erratically.
With the teachers, like Dumbledore, he might be treated differently. Dumbledore might see this transformation as an opportunity for Harry to learn new things about the wizarding world from a different perspective. And some of the more traditional teachers might have different expectations of Harry's behavior in class now that he is a girl.
Ash's transformation into a Gardevoir would have a complex impact on his relationships. Some Pokemon that were once his rivals might see him in a new light and either be more respectful or more envious. His bond with his own Pokemon team would change too. They would have to adapt to his new abilities and appearance. And he would form new relationships with Pokemon that are more associated with Gardevoir's kind, like other Psychic or Fairy - type Pokemon.
It can strain his relationships. If the experiment gives him new powers that are hard to control, he might accidentally harm his loved ones, causing distance. For example, if he has a new power that causes electrical shocks, he could shock his friends when he doesn't mean to.
The transformation of Harry Potter into a werewolf in the fanfiction could have a huge effect on his relationships. His enemies might use it against him, and his allies might have to work harder to protect him. Also, it could change how he sees himself and how he interacts with the magical world as a whole.
His friends might be initially terrified. Hermione, for example, would be both scared and immediately start researching how to reverse it. Ron would probably be more shocked and not know how to react at first. Their friendship would be tested as they try to figure out what to do. They might have to keep Harry's transformation a secret from other students to protect him from being hunted or experimented on.
When Spider - Man's identity is revealed in fanfiction, it can have a huge impact on his relationships. For example, his romantic relationships might become more complicated. His partner might be in danger more often because his enemies now know who he loves. His friendships could also change. Some friends might be proud of him, while others might be scared and distance themselves. And his relationship with his family would be under a lot of stress, as they worry about his safety more than ever.
Well, his friends might be initially shocked. Some, like Shikamaru, would probably quickly analyze the situation. Sakura might be a bit worried at first but then try to find a way to reverse it. His closer friends like Sasuke, in his own way, might see it as just another quirk of Naruto's and still accept him, though it could add some new dynamics to their interactions, like how they fight together or just hang out.