On the other hand, Harry might also be somewhat relieved. The lordship comes with a lot of responsibilities and expectations. If he has doubts about his ability to handle it, Dumbledore's attempt could seem like a way out, at least at first.
Harry might be initially confused. He has just found out about his lordship and now Dumbledore wants to take it away. He would likely question Dumbledore's motives.
Maybe Dumbledore believes Harry isn't ready for the responsibilities that come with the lordship. Harry is still young and has a lot to learn about the wizarding world's politics and social structures. Dumbledore may want to protect Harry from making hasty or unwise decisions in a position of power.
Harry might initially be confused. He has always looked up to Dumbledore, so when he realizes Dumbledore is trying to control him, he could start to question everything he thought he knew about their relationship. He may become more rebellious as a result, trying to break free from Dumbledore's influence and make his own decisions.
Hermione might support Harry if she also sees some flaws in Dumbledore's leadership. She is very logical and if Harry presents her with solid evidence, she could side with him. For instance, if Dumbledore's actions are putting students in danger in some way, Hermione would want to protect her fellow students.
If Dumbledore punishes Harry severely, it could lead to a rift between them. This might make Harry more rebellious and drive him to take actions on his own without Dumbledore's guidance, which could put him in more dangerous situations and greatly change the direction of the story.
At first, Harry may be in shock. He's been taken by someone he respects and looks up to. As he comes to terms with his situation, he might try to reason with Dumbledore. If that doesn't work, he could start to plan an escape, using his wits and the magic he knows. He might also feel angry that Dumbledore is treating him this way when he's always been on Harry's side, or at least that's what Harry thought.
At first, Harry is likely to be shocked. Discovering that someone he trusted so much, like Dumbledore, has been lying to him is a huge blow.
There would also be fans who are simply curious. They might want to read the fanfic just to see how the author justifies Dumbledore's actions. Whether it's because of some dark prophecy or a misunderstanding, they would be interested in seeing how the story unfolds and if the author can make this rather controversial concept seem plausible within the magical world of Harry Potter.
Sirius would probably be shocked at first. Then, he'd likely feel a deep sense of sadness and guilt. He might think that he should have been there more to protect Harry from getting those scars.
He might be motivated by a desire to protect Harry's reputation. Fanfiction can be full of wild and untrue stories, and Dumbledore doesn't want Harry to be misrepresented.
Well, Dumbledore has always had a special connection with Harry. When he finds out about the abuse, he would be devastated. His first instinct would be to comfort Harry. He might also reflect on his own actions and whether he could have prevented the abuse from happening. Dumbledore would then use all of his resources to make sure Harry is safe and happy. He could provide Harry with a mentor or a guide to help him through the difficult times, someone who can teach Harry how to cope with his past and move forward in a positive way.