Well, Harry Potter would probably have a range of reactions. If the fanfiction shows his friends in a positive light or gives more depth to the relationships he had at Hogwarts, he might feel a sense of warmth. But if it distorts the characters too much or goes against the basic principles of good and evil in the wizarding world, he could be quite perturbed. For example, if a fanfiction made Hermione act completely out of character, he might be disappointed. He's used to the real Hermione and her strong sense of justice and loyalty. Also, if the fanfiction delved into new areas of magic that were not in the original books but still felt in line with the magical system, he might be intrigued.
Some teachers might be amused. For example, Hagrid, being a kind - hearted and simple - minded character, would probably chuckle at the creative and often wild ideas in fanfictions. He might enjoy seeing new adventures of Harry and his friends, even if they're not part of the original story.
Well, they might be quite surprised. The Highschool DxD characters are used to their own world of devils, angels and the like. When exposed to Naruto fanfiction, they could be intrigued by the ninja concepts. For example, Issei might be excited about the idea of having ninja powers added to his already powerful abilities. He might think it's really cool how the ninjas in Naruto can use jutsu and he might even start imagining himself using some of those techniques in battle.
In some fanfictions within 'Harry Potter and the Legacy of Hogwarts', there could be a plot about time - travel. A group of students accidentally travel back in time and witness key events in Hogwarts' history. This could lead to them learning important lessons that they bring back to their own time. Or perhaps a plot where a new magical creature is discovered near Hogwarts and it has a special connection to the school's legacy. The students then have to protect the creature and in the process, learn more about the deep - seated magic that has been passed down through the generations at Hogwarts.
Some of the RWBY villains might be intrigued by the strategic elements in Red vs Blue fanfiction. In RWBY, they are used to battles with semblances and dust, but in Red vs Blue, the battles rely more on regular weapons and teamwork in a different way. They could analyze these new strategies and perhaps even consider applying some concepts to their own plans in RWBY, if possible.
One idea could be a story about a new student who discovers a long - forgotten magic spell in the Hogwarts library that has the power to change the appearance of the entire school. Another could be a fanfiction where the characters have to deal with a strange magical illness that only affects those with a certain type of magic bloodline.
Harry might be somewhat critical. He has his own set of values and beliefs based on his experiences in the wizarding world. He may not like how some characters in the fanfiction are portrayed if they deviate too much from what he considers 'right' in terms of heroism and friendship. He might also be a bit jealous of some of the unique magical items in Lord of the Rings that are not present in his world.
He might be quite intrigued. Fanfiction often takes the existing world and twists it in new ways. Harry would probably be interested in how different writers portray the Fantastic Beasts universe. Maybe he'd be excited to see new takes on the magical creatures he loves, or perhaps he'd be a bit critical if the fanfiction deviated too much from what he knew about the wizarding world.
One challenge could be dealing with the traditionalist teachers and pure - blood families. They might resist any changes Harry tries to make as they are used to the old ways. For example, if Harry wants to introduce muggle - born friendly policies, some of the old - school pure - bloods might oppose it.
Well, the teachers at Hogwarts might be quite surprised. Dumbledore would probably be amused and see it as a creative expansion of the wizarding world he knows so well. McGonagall might be a bit more critical, worrying about how it adheres to the proper magical lore. And the students? They'd likely be excited, finding new and different takes on their own adventures and the characters they love.
Often, there are original characters who are powerful young witches or wizards. For example, a character who has a special ability to communicate with magical creatures in a unique way. Another popular type could be a character who is a descendant of an old Hogwarts founder but was previously unaware of their heritage.