After reading the fanfiction, Percy could have a more in - depth understanding of the wizarding world. He might start to think about how the social structure in the wizarding world compares to that in his demigod world. He might also be more curious about the history and lore of the wizarding world, and how it developed compared to his own world of Greek gods and monsters. He could even start to imagine what it would be like to be a wizard, with all the unique spells and magical items, and how that would change his approach to dealing with his own problems.
A character like Dumbledore might read fanfiction with alternate timelines. This could make him reflect on the choices he has made in the real wizarding world. He might start to consider if there were other paths that could have been taken to achieve the same or better results. It could also make him more aware of the potential of different futures for the wizarding world.
Their view might expand. They'd see different takes on the wizarding world that they hadn't considered before.
They may gain a deeper understanding of how the outside world perceives their world. Fanfiction often reflects the hopes, dreams, and fears that fans have about the wizarding world. So, by reading it, the Potter family can get a sense of what others find interesting or concerning about their world. For instance, if a lot of fanfiction focuses on the social inequalities in the wizarding world, it might make them more aware of these issues and perhaps even inspire them to do something about it.
His view could become more open - minded. He'd realize there are other ways to approach the supernatural world. For example, the way the hunters in Supernatural use weapons instead of wands might make him think about alternative forms of magic defense.
Their view could become more confused. Fanfiction can present all sorts of alternate universes and character developments. The Death Eaters, used to a very specific view of the wizarding world under Voldemort, would find it hard to accept different versions. They might see the wizarding world in fanfiction as a chaotic and wrong place, which would make them double down on their own views to feel more secure.
Reading fanfiction would expose them to the creativity of the wizarding community. They might find new interpretations of magic that they hadn't thought of before. Some fanfictions could also show different relationships between characters, which could make them think about their own relationships in a new light. They might also be a bit concerned if some fanfictions spread false information about important events or people in the wizarding world, but overall it would give them a broader understanding of how the wizarding world was seen by those outside their immediate circle.
His view could become more nuanced. If the fanfic shows different versions of the events in the 'House of Hades', he might start to see the original story in a new light. For example, if a fanfic focuses on a side character's perspective during the events in the 'House of Hades', Percy might realize there were more things going on than he initially thought.
If Harry invented spells like 'Teleporto Instanto', which allows for instant teleportation anywhere in the wizarding world, it would completely revolutionize travel. People could go from Hogwarts to Diagon Alley in a blink. It would also change the way battles are fought as wizards could quickly escape or surprise their enemies.
His perspective could expand. He might start to consider new possibilities within the wizarding world. For example, if a fanfiction introduced a new relationship between a Fantastic Beast and a wizard, he'd think about how that could work in the real wizarding world.
The wizarding world would likely be plunged into a state of despair. Harry was seen as the 'Chosen One' to defeat Voldemort, so without him, there would be a sense of hopelessness. Voldemort would probably have free rein to impose his dark rule without much opposition at first.