The teachers, like Professor McGonagall, would take charge. She would ensure that Harry was moved to a more comfortable and safe place, like the hospital wing. And she would start an investigation into the matter, asking the other students if they saw anything strange before Harry fainted in the Great Hall.
Hermione would likely be the first to rush to his side. She would immediately start using her knowledge of magic to try and figure out what was wrong with him. She might cast diagnostic spells and try to find a cure if it was something she could handle on her own.
Ron would be very worried and would probably stand there looking a bit panicked at first. But then he would do whatever Hermione told him to do to help Harry. He might also get angry and start looking for whoever or whatever was responsible for Harry fainting.
Some characters like Hermione might be really surprised. She might raise her eyebrows and think it's quite out of the blue. Ron, on the other hand, would probably be more shocked and might even choke on his food if he was eating at that moment.
His friends like Pikachu would be very worried. Pikachu would probably stay by Ash's side, trying to use its electric shocks gently to revive him. Misty might scold Ash for being so reckless but also show concern by getting water to cool him down. Brock would immediately start checking Ash's vital signs and try to figure out what went wrong.
Ron would be extremely angry at first. He might feel betrayed by Harry. But as he realizes that something must be seriously wrong with Harry, he would probably join Hermione in trying to save Harry from Voldemort's influence. They would look for a way to break whatever spell or false belief has hold of Harry.
Dumbledore would likely view it as another sign of Harry's individuality. He would see it as Harry growing up and making his own choices, as long as it doesn't interfere with his destiny. Snape might sneer at it, thinking it's just another Gryffindor folly. But secretly, he might respect Harry's courage to do something different.
The other characters' reactions would vary widely. Ginny would be heartbroken. She might feel that Harry has abandoned not just his identity but also their relationship. Neville would be shocked and would probably feel that Harry has let down the whole school. Some of the Slytherins might be secretly glad, thinking that it removes a threat to their own ambitions. However, many of the younger students who looked up to Harry would be confused and disappointed, as he was a symbol of hope for them. Teachers like McGonagall would try to keep the school together in the face of this chaos, while also hoping that Harry would return.
Hermione, on the other hand, would likely have a more critical view. She'd analyze the fanfictions for their accuracy in terms of magic lore and Hogwarts traditions. If there were any inaccuracies, she'd be quite perturbed. However, she might also appreciate the creativity that goes into some of the well - written ones that add new dimensions to their magical world.
Hermione would probably be very confused at first. She'd try to understand the reasoning behind it and might be worried that Harry has lost his sense of self. Ron would likely make jokes about it, but also be a bit concerned. Dumbledore, on the other hand, would probably see it as another step in Harry's journey of self - discovery and would encourage him to explore what this new identity means. Voldemort might see it as a sign of weakness or a strange ploy by Harry, but would still be cautious as he doesn't fully understand the implications of this new name.
The students would have a wide range of reactions. The Gryffindors might be more vocal about their surprise, with some being more accepting than others. The Slytherins would be more divided. Some of Snape's loyal Slytherin students might be protective of him, regardless of his new form, while others might see it as a sign of weakness. Draco Malfoy would probably be initially disgusted but as he sees Snape still maintaining his authority, he might change his attitude. And the Hufflepuffs would generally be more kind - hearted and accepting, perhaps offering Snape small tokens of support like homemade treats or kind notes to help him through this difficult change.
The Order of the Phoenix would see Harry's joining of the Death Eaters as a major setback. They would likely view it as a sign that Voldemort has become even more powerful. Dumbledore, if he were still alive, would be very concerned and would try to understand what led Harry to this decision. He would also be devising a plan to get Harry out of the clutches of the Death Eaters.
The other Gryffindor students would have a range of reactions. Some of the more open - minded ones would cheer Harry on, seeing it as a brave and unique thing to do. The more traditional ones might be a bit taken aback. Snape would likely be disdainful, but secretly a bit intrigued. He might even use it as an excuse to give Harry a hard time in Potions class. Hagrid would just be his big - hearted self and say something like 'Harry, yer always full o' surprises!' And Luna would probably think it was perfectly normal and start a conversation about how cross - dressing can be a form of self - expression in the wizarding world.