They might be amused. They could find some fanfictions that depict them in ways they never thought of, which might make them chuckle at the creativity of the fans.
They could also be intrigued. Some fanfictions might introduce new plotlines or character developments for them. Maybe a fanfiction shows a backstory for Toga that makes her more sympathetic, and they would be interested in seeing this new take on their comrade.
They might think it's a strange and fascinating alternate view of the world they know. They could be amused by how fans re - imagine the events and characters from HTTYD 1. Maybe they would be a bit jealous if the fanfiction makes the heroes seem even more heroic than in the original movie.
Well, Cinder would probably be a bit annoyed if the fanfic doesn't portray her as powerful as she thinks she is. She has a huge ego and seeing herself as weak or less important in a fan - created story could really irk her. On the other hand, if the fanfic shows her in a really cool and dominant way, she might secretly enjoy it.
They might be amazed by the different interpretations of the Justice League characters. Ruby could be excited to see new heroic feats, Weiss might analyze the writing style, Blake could be interested in the relationships, and Yang would probably enjoy the action-packed parts.
For heroic - centric fanfictions, they would likely be disdainful. Since they oppose heroes, seeing stories that glorify heroes would annoy them. They might scoff at the idealized versions of heroes in those fanfictions.
They might be really intrigued. Some like Midoriya would be taking notes on the unique storylines and character developments in the fanfiction, comparing them to his own experiences with quirks and heroism.
The Justice League would be in for a revelation. Goku's 'I Am' speech is not just about power but about self - discovery. They'd notice how Goku's values are different from their own in some ways. For example, Goku's focus on personal growth through combat. They might also be inspired to be more open about their own identities and not be so bound by their superhero personas.
They might be quite surprised. Some characters could find it strange to see their own stories being reimagined in different ways by fans. For example, if Sherlock Holmes were to watch elementary fanfiction, he might be intrigued by the new interpretations of his deductive reasoning skills or his relationships with other characters like Watson.
The characters might also feel a sense of flattery. If they see that the fanfiction writers are so passionate about their world and go to great lengths to create these stories. Kristoff, for instance, might be happy that fans are interested enough in his character to include him in different adventures in the fanfiction, even if those adventures are a bit far - fetched from his real - life (in - the - movie - life) experiences.
He might be really surprised. He could find it strange to see different versions of his own story and the people around him in the fanfiction.
Ruby could find the fanfiction inspiring for her own battles and teamwork ideas. Weiss might note any differences in the magic system or how the kingdoms are portrayed. Blake may analyze the themes of love and family in the fanfiction. Yang would enjoy the action - packed parts and might even get some new ideas for her own fighting moves. Overall, they would all have different perspectives based on their own personalities and experiences.