Luna would likely have a very unique reaction. She might think that Harry turning into a cat is part of some grand, magical plan that no one else understands yet. His other friends like Seamus and Dean would be both amused and worried. They'd try to keep Harry's transformation a secret from the teachers at first, in case they got into trouble, but also look for ways to reverse it.
His friends would be quite shocked. Neville might be a bit scared at first, thinking it's some new dark magic. But then they'd all come together. Ginny would probably be the one to try and comfort 'cat - Harry' by giving him some fish or milk, thinking that's what cats like. And they'd all be determined to get him back to normal as soon as possible.
Ron would probably be both shocked and a bit awestruck at first. He might make some typical Ron - like jokes to ease the tension, like 'Blimey, Harry, you're a dragon! At least you'll be good for scaring off Snape now!'. But deep down, he'd be worried and determined to help Harry get back to normal.
Well, if Harry turns into a cat, Hagrid would be quite worried. He might try to take care of Harry in his cat form, giving him treats and a warm place to sleep. The other students would have a mix of reactions. Some might be scared, thinking it's some sort of dark magic at work. But his closer friends like Neville would be determined to help. Neville might even try some of his own plant - based magic to see if it could help Harry turn back. Snape, of course, would probably be skeptical and think Harry got himself into this mess on purpose.
At first, his friends would be in disbelief. But then, they would start to adapt. Dawn might see it as an opportunity to study a Pokémon from a different perspective. Gary could be both amused and intrigued, and might offer some scientific theories on how it happened. Overall, they would all be concerned for Ash's well - being and work together to either help him get back to normal or help him thrive in his new form.
I think his friends' reactions would vary. Naruto's closest friends like Shikamaru and Kiba would quickly realize that they need to support Naruto. They would see that despite the strange new form, it's still Naruto. Sakura would be more emotional, she might cry at first but then pull herself together to help. And Sasuke, he would probably see it as an opportunity for Naruto to gain more power, but also be cautious in case the Titan form has any negative effects on Naruto's mind.
His friends would be very shocked at first. Misty might be a bit worried and try to find a way to turn him back quickly. Brock, on the other hand, would be more curious and start observing Ash - as - Pikachu to see how his behavior has changed. His Pokémon friends would also be confused. Pikachu himself might be both excited to have a 'Pikachu - like' friend but also a bit sad that his trainer is in this strange state.
At first, his friends would be shocked. Hermione might think it's some kind of dark magic at first glance. But as Harry shows them what he can do, she would start to analyze it scientifically. Ron would be more awed. He'd be like a kid seeing a new cool trick. They would both support Harry in exploring this new ability, but also be a bit cautious as they don't fully understand where it comes from or what the implications are in their wizarding world.
His friends would be very surprised. Hermione would probably be a bit skeptical at first. She'd want to research all about Witchers before she fully supported Harry's new interest. Ron, on the other hand, might be more excited. He'd see it as another adventure and would be eager to hear all about the Witcher world from Harry.
Luna would likely have a very unique reaction. She might say that the fanfiction is just another form of magic in the world of imagination. She could tell Harry that he should embrace it in a way, as it shows how much people are interested in his story, even if it is a bit mortifying at first. But she would also respect if he was really bothered by it.
His friends' reactions would be mixed. Shikamaru would be like 'This is such a drag.' But he'd also start thinking of strategies to deal with the situation. Ino would be all about helping Naruto with his new look, like suggesting new outfits that would suit a fox girl. Choji would be more focused on making sure Naruto is still the same person inside. He'd offer Naruto his snacks to cheer him up. And Hinata would be blushing a lot, but also be very supportive, saying things like 'Naruto - kun, you look... different, but you're still you.'
Sakura might be initially shocked and a bit jealous at how cute Naruto - as - a - girl is. Sasuke would probably be confused at first but then act indifferent. Kakashi would be his usual calm self, but might crack a few jokes about Naruto's new look.