Hermione would be the first to adapt. She'd start making connections between magic and Pokemon abilities. For instance, she might compare the Confundus Charm to a Pokemon's ability to cause confusion in battle. Ron would initially be a bit skeptical but would soon get into the spirit when he realizes there are some really cool and strong Pokemon. He might try to catch a large and imposing one to show off. Neville would see the Pokemon world as a new opportunity to grow. He'd be gentle with the Pokemon, especially those that are small and fragile, and his love for plants would translate into a love for grass - type Pokemon.
Ron might see it as another adventure that Harry is having and would be eager to join in, even if he doesn't fully understand it at first. He'd be excited to see the different Pokemon and might even try to catch one with Harry. Hermione would approach it more analytically. She'd question how the Pokemon world operates, what the rules of Pokemon training are, and how it could potentially affect the wizarding world. She might be a bit worried about any potential negative impacts.
Hermione would probably be a bit worried at first. She might think it's a waste of time compared to studying magic. But then she'd see the benefits of physical fitness and start to support him. Ron, on the other hand, would probably make fun of him a little but also be secretly impressed.
Hermione would probably be very curious. She'd want to study the Digimons and their world, and would likely try to find books or sources of information within the Digimon World itself. Ron, on the other hand, might be a bit more hesitant at first but would soon get excited about the new adventures.
Some students would be super excited. The younger students especially would be thrilled to see cute Pokémon like Eevee around the castle. They would be eager to learn from them and make friends with the Pokémon.
They would probably be shocked at first. I mean, Hogwarts reading fanfiction? It's a strange concept. But then they might be really curious about what Hogwarts is reading. They could try to get their hands on the same fanfiction to see what all the fuss is about.
Flitwick might be quite intrigued. He loves magic in all its forms and fanfiction would show him new and different ways magic could be used in the Harry Potter world. He'd be interested in the creative spells and concepts that the fans come up with.
There would be shock and disbelief. The wizarding world has always seen Hogwarts as a symbol of hope, knowledge and safety. If Harry destroys it, many would be in denial at first, thinking it couldn't be true. Wizards and witches from all over would come to the ruins, trying to figure out what had happened.
The characters' reactions would be diverse. Snape would likely be very critical and use it as another reason to dislike Harry. He might see it as a sign of Harry's lack of respect for the wizarding world's traditions. The other students would be a mix of those who are fascinated by this strange Muggle object and those who are worried about its potential for harm. Hagrid would be confused, not really understanding what a gun is but knowing it doesn't seem right in Hogwarts. Overall, it would create a stir among the Hogwarts community and lead to a lot of discussions and speculations.
Ginny would be protective. If there were any fanfictions that she thought were disrespectful to Harry or painted him in a bad light, she'd be angry. But she'd also enjoy the ones that showed the depth of his character and his relationships with others, especially the ones that highlighted his relationship with her.
Hermione would probably be worried at first but then start researching all she can about space magic. Ron would be a bit more skeptical but also excited for Harry. They might try to find a way to communicate with him while he's in space, using some sort of enchanted device.