His mobility would change drastically. He could fly to class instead of walking, which would be a huge advantage in terms of time - saving, but also might get him in trouble with the school rules. For example, flying in the corridors is usually not allowed.
In a more profound way, Harry's self - identity could change. He has always been known as 'the boy who lived' and for his Gryffindor courage. But now, with butterfly wings, he becomes something new and different. He might start to question his place in the wizarding world. Does he belong more with the magical creatures because of his wings? Is he still just a regular wizard? These internal conflicts could drive the story in many interesting directions as he tries to figure out who he is with this new physical feature.
Harry's relationships might also change. Some students might be in awe of him and want to be his friend just because of his wings. However, others might be jealous. He would also have to deal with the stares and whispers. But overall, his wings could give him a new sense of confidence and independence, allowing him to face his enemies, like Voldemort, with a different kind of courage.
His life would become more complex. He would have a new family bond to consider. He'd likely be more protective and might start to think about his future in terms of his sister as well.
Hermione would probably be very curious at first. She'd immediately start looking through all her books to find any information about such a strange transformation. Ron, on the other hand, might be a bit more freaked out. He'd probably make some jokes at first to cover up his unease, but then he'd be there to support Harry. Ginny would likely be concerned but also find it kind of cool and would try to help Harry get used to his new wings.
If Harry Potter becomes part of a Pokemon fanfiction, his life would change in many ways. Firstly, his daily routine would be different. Instead of going to magic classes, he'd be out in the wild looking for Pokemon. His friends might also change as he'd befriend other Pokemon trainers. His relationship with magic might even be affected. He could start using magic in new ways related to Pokemon, like using spells to communicate with them. And his sense of adventure would be redirected towards exploring the different regions in the Pokemon world.
His focus would shift from just magic and wizardry to also include the world of animations. He'd probably be constantly thinking about the next animation he wants to watch.
His view of heroism would change. Hellboy is a very different kind of hero compared to the wizards in Harry's world. He's more of a brawler and has a darker, more gritty approach to fighting evil.
His life would change drastically. He'd be surrounded by Death Eaters and the dark side of magic. His values would be challenged, and he might not have the same friends. He could become more feared in the wizarding world.
He'd probably have a different accent. And his diet might change too, more burgers and fries perhaps. His view of the wizarding world could be more influenced by American values like equality and freedom.
His daily routine would change a great deal. Instead of waking up to the cold and often dreary UK weather, he'd wake up to the warm sun of Hawaii. He might start his days with a swim in the ocean rather than a walk around the Hogwarts grounds.
If Harry had no eyes, his experience at Hogwarts would be transformed. He couldn't read textbooks in the traditional way. Maybe he would use magic to have the words read to him. His interactions with magical creatures would be different too. For example, when facing a basilisk, he couldn't look it in the eye to defeat it, so he would have to find another way, perhaps using his sense of smell to detect its presence and then cast spells blindly in its direction.