The older characters such as Kakashi would be cautious. They would recognize Naruto but also be worried about the implications of someone from the future being in the present. They would want to know if his presence could change the future in a negative way. For example, they might fear that his actions could lead to the earlier awakening of a powerful enemy. As for the villains, they might see future Naruto as a threat and try to eliminate him as soon as possible. Orochimaru, for instance, would be very interested in Naruto's future powers and might try to capture him to study. And the new generation of ninja in the past would look up to future Naruto, seeing him as a symbol of what they could become.
Hermione Granger is also a likely character. Her intelligence and love for knowledge could lead her to discover a way to bridge the past and the future. She might use her Time - Turner knowledge or find some new magical method. And she could play a key role in helping past characters adapt to the future or vice versa.
At first, he may be in disbelief. But as he starts to understand what he's seeing, he could become solemn. He realizes the weight of the future and the responsibility he may have to shape it in a positive way. He might also feel a bit of fear, especially if he sees the loss of his friends or loved ones. But overall, his Gryffindor courage would likely kick in, and he'd start to think about how to face whatever the future holds.
Hermione, on the other hand, would likely have a more critical view. She'd analyze the fanfictions for their accuracy in terms of magic lore and Hogwarts traditions. If there were any inaccuracies, she'd be quite perturbed. However, she might also appreciate the creativity that goes into some of the well - written ones that add new dimensions to their magical world.
The professors at Hogwarts would have different reactions. Professor Snape might be secretly intrigued by this new and strange creature while outwardly showing disdain. Professor McGonagall would be concerned for the safety of the students and would start organizing protection spells around the school. Hagrid, being the lover of strange creatures, might try to approach it in a friendly way at first, until he realizes how dangerous it is.
Well, if Harry goes back in time, his actions could have a huge impact on the future. For example, if he saves a character who was supposed to die, it could change the entire story. Maybe he saves Cedric Diggory in the Triwizard Tournament earlier than he should have. This could lead to Cedric having a major role in the fight against Voldemort later. Also, if he changes the relationships between characters in the past, like making Snape and Lily closer friends, it could change Snape's attitude towards Harry in the future.
In a Harry Potter fanfic where past meets future, it often works through time - travel magic. For example, a character might use a Time - Turner or some other magical device to journey from the present or future to the past. This can create all sorts of interesting scenarios. They could meet their younger selves, or change events that were thought to be set in stone. It also allows for crossovers between different generations of characters, like Harry meeting his parents when they were at Hogwarts. This kind of plot device can bring new perspectives to the well - known Harry Potter universe and open up a whole new world of storytelling possibilities.
The Weasley family would have different responses. Mrs. Weasley would be motherly and concerned about this strange new person. Fred and George would see her as a source of new ideas for their pranks and inventions. Ginny would look up to her as a strong female figure, much like she does with Hermione. And all of them together would gradually get used to having Powergirl around, and they would all grow from the experience of interacting with someone from a completely different world.
Harry would likely be very conflicted. He has seen a lot of death and has always fought against dark magic. The Death Note's power to kill just by writing a name is something that goes against his values. He would probably try to keep it away from others and might even consider destroying it.