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.
His Gryffindor friends would likely be supportive in general. They're used to Harry's unique interests and adventures. Ginny would be interested in the strong female characters in the Witcher world, if there are any. And Seamus and Dean would probably joke around about Harry becoming a Witcher - like figure in the wizarding world, but secretly they'd be a bit envious of his new and exciting discovery.
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.
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.
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.
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.
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.
Sakura would probably be a bit skeptical at first. She might worry that Naruto is getting distracted from his ninja duties. But once she sees how passionate he is, she would support him and might even help him with his training regime, using her medical knowledge to make sure he's in top physical condition for racing.
His friends would be very shocked at first. Sasuke, for example, might be suspicious of this new Naruto. But once he realizes that Naruto is still the same at heart, he would start to accept it. Sakura would probably be worried about Naruto's well - being and try to find a way to reverse the change if possible.
Sakura might be a bit confused at first. She's focused on her medical ninja training and Naruto's sudden interest in Lunney seems out of left field. But she would probably be supportive in the end, especially if Naruto could show her how Lunney's ideas could be relevant to their lives. Sasuke, on the other hand, would likely be dismissive. He has his own goals and Naruto's newfangled interest might seem like a distraction to him. However, if Naruto could prove that Lunney's concepts could help in their fight against common enemies, Sasuke might change his tune.
His friends' reactions would be mixed. Naruto's closest friends, like Choji and Ino, would be really worried about him. They'd be sad to see him change into something so different from the Naruto they know. But at the same time, they would also be curious about his new powers. Sasuke, if he's around, might be a bit more aloof at first. He'd see Naruto's transformation as another sign of Naruto's growth and might even be a bit jealous that Naruto has gained these new and potentially powerful abilities.
Sasuke would probably be initially shocked. But then he'd be all about finding a solution. He might even sacrifice some of his own power to try and save Naruto. Sakura would be horrified and would immediately start researching any medical jutsu that could reverse the process.