Hermione would immediately start researching. She'd try to find out all she could about Freddy, his weaknesses and the nature of his power. She might dig into ancient magic texts to see if there are any spells that could be used to banish him from the wizarding world or the dreams of the students.
Harry would probably be very brave and try to face Freddy head - on. He's used to dealing with dark forces, so he'd likely attempt to use his magic against Freddy. For example, he might try to stun him with a Stunning Spell.
In a fanfiction where Harry Potter is raised by Freddy Krueger, it's likely that Harry would have a very different personality. He'd probably be more fearless in a strange way because he's been around such a terrifying figure all his life. However, he might also struggle with his own identity. Is he a wizard or something more like Freddy? His relationships with other characters like Hermione and Ron would be extremely different, as he'd have a much darker upbringing to draw from.
The story would be unrecognizable. Harry's upbringing by Freddy Krueger would mean that he has no concept of the love and friendship that are so central to the original Harry Potter story. He'd be used to a world of nightmares and fear. His interactions with the other characters would be full of conflict. For example, he might see his classmates as easy prey rather than friends. His relationship with the teachers at Hogwarts would be strained as they try to understand and correct his behavior. And the overarching plot of the fight against Voldemort would be replaced with something much more sinister as Harry's values are completely different from what they are in the original story.
It would be really strange. Harry is all about good and magic, while Freddy is a symbol of horror. Maybe in the fanfiction, they could meet in some sort of alternate dimension. Harry might try to use his magic to understand Freddy's dark nature and gradually fall in love. But it would be a difficult relationship to write realistically.
Some characters might be quite amused. For example, Hermione would probably analyze the fanfiction from a logical perspective, critiquing the plotlines that involve ships. Ron, on the other hand, might be a bit bewildered at first but then find it rather entertaining. Harry himself could be either indifferent or intrigued, depending on how the ships are portrayed. If it's a ship that he has a personal connection to, like his parents, he might be more interested in seeing how the author has envisioned their relationship in the fanfiction world.
Dumbledore would likely be very accepting of Stitch. He has a great understanding of all kinds of creatures and beings. He would see Stitch's potential for good and might even try to find a place for him at Hogwarts. Snape, however, would be more skeptical. He would keep a close eye on Stitch, worried that he might disrupt the order of the school or cause harm to the students. The Weasley twins would probably find Stitch hilarious and would want to play pranks with him or use his unique abilities for their own mischievous plans.
Draco Malfoy would probably be outraged at first if he read fanfiction that showed him in a positive light towards Harry and his friends. He's so used to being on the opposite side, but then he might secretly be a bit flattered by some of the more complex characterizations of him.
In a fanfiction, the students at Hogwarts would be really intrigued by Hawkeye. They've grown up in a world of magic, and Hawkeye would represent a different kind of power. Neville might look up to Hawkeye as someone who uses their own skills to fight, without relying on magic. Ginny would probably be eager to team up with Hawkeye in any battles or adventures, seeing his potential as an ally in the fight against evil.
Hermione would probably be very curious about Darkseid at first. She'd try to research him in the Hogwarts library, looking for any clues about his powers and weaknesses. But once she realizes the danger he poses, she'd be quick to come up with strategies to fight him.
Hermione would be extremely curious. She would immediately start researching it, trying to figure out its mechanics and where it came from. She might even try to find a way to improve it or adapt it to the wizarding world's technology.
In a crossover, Voldemort could team up with Freddy Krueger. Voldemort, seeking more power, might see Freddy's ability to manipulate dreams as a useful tool. However, the Hogwarts crew would have to figure out how to fight this unlikely and dangerous alliance. They would need to combine their knowledge of magic and the nature of dreams to stand a chance.