How would the characters in Harry Potter react if Harry becomes the overlord in fanfiction?

Some of the more progressive magical families like the Weasleys might side with Harry. They've always been on the side of good and if Harry shows that his rule would bring positive changes to the wizarding world, they'd be his allies.

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.

The wizarding world would be in shock. People who once idolized him would feel betrayed. The Ministry of Magic would probably declare him a most wanted wizard and send out Aurors to capture him.

There would be a great uproar. The pure - blood families who are used to the old ways and the power structure of the Ministry would be horrified. They would see Harry as a rebel who is disrupting the peace. However, the younger generation of wizards, who have grown up hearing about Harry's adventures and heroics, might be inspired. They could start to question the inefficiencies of the Ministry and support Harry's vigilantism, which could lead to a generational divide in the wizarding community.

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.

Hermione would probably be very curious. She'd immediately start researching in the library to find out if there are any known cases of wizards having tails and how to reverse it if it was an unwanted condition. Ron, on the other hand, would likely make some jokes at first, but then be supportive. He might say something like 'Well, at least it makes you stand out even more, Harry!'. Dumbledore would be his usual calm self. He might see it as a sign of something greater or a test for Harry, and offer some cryptic advice.

Hermione would probably be both curious and worried. She'd want to research all about Harry's half - demon nature to find out what it means and how to help him. Ron, on the other hand, might be a bit more hesitant at first. He might be a bit scared but would eventually come around because of his loyalty to Harry.

Some characters might be excited. They could see him as a new source of knowledge and magic.

The Weasley family would have different responses. Mrs. Weasley would be motherly and concerned about this strange new person. Fred and George would see her as a source of new ideas for their pranks and inventions. Ginny would look up to her as a strong female figure, much like she does with Hermione. And all of them together would gradually get used to having Powergirl around, and they would all grow from the experience of interacting with someone from a completely different world.

Batman would probably be very cautious at first. He'd want to study Harry and his magic to see if it could be a threat or an asset. The Joker might see Harry as a new plaything, a strange and magical being to toy with. Commissioner Gordon would likely be intrigued and hope that Harry could help clean up Gotham's streets.