The power dynamics shift significantly. Instead of Dumbledore being the all - knowing guide, Harry becomes more of an independent force. This could lead to a more chaotic battle against Voldemort as Harry might not follow Dumbledore's strategic plans.
The overall tone of the story could become darker. With Harry challenging Dumbledore, the sense of unity and hope that Dumbledore usually represents is fractured. This could lead to a more desperate and uncertain fight against Voldemort as the wizarding world is divided over this internal conflict.
The change in the storyline would be multi - faceted. Emotionally, Harry would be on a different journey. He would be dealing with feelings of betrayal (if he believes Dumbledore has wronged him) and determination to prove himself right. In terms of the plot, the search for Horcruxes might take a different turn. Harry might not follow Dumbledore's clues as closely. He could end up finding Horcruxes in different ways or even missing some if he doesn't have Dumbledore's wisdom. And the final confrontation with Voldemort would be more unpredictable. Harry's rebellion could lead to a more evenly matched battle as he might not have all the advantages that Dumbledore's guidance would have provided.
One reason could be a difference in ideology. Harry might have come to believe that Dumbledore's methods, like keeping secrets from him, are not in the best interest of the wizarding world. For example, Dumbledore withheld information about Harry's connection to Voldemort which put Harry in more danger at times. Harry could stand up to him to demand more transparency.
It might make Harry more confident. With Dumbledore's training, Harry gains more knowledge and skills, which gives him the confidence to face challenges.
In terms of the overall plot, it can take a completely different turn. Instead of Dumbledore having a master plan to defeat Voldemort, it might be up to the younger characters to figure out everything from scratch. This makes the fanfiction more of a coming - of - age story where the kids have to face the ultimate evil without the safety net of a competent Dumbledore.
At first, it would likely strain their relationship even more. Snape is used to having the upper hand and Harry's defiance would anger him. But in the long run, it could lead to a grudging respect from Snape. He might start to see Harry as more than just James Potter's son and realize that Harry has his own strength of character.
Well, Harry's character development could be quite complex. He might initially be shocked or even angry when he 'turns on' Dumbledore. As he delves deeper into his new feelings, he could start to question his own beliefs and values that were influenced by Dumbledore. This could make him explore different magical paths or ways of fighting against Voldemort. For example, he might look into more radical or unorthodox methods instead of relying on Dumbledore - inspired strategies.
The relationship would become very strained. Harry's rejection would likely make Dumbledore re - evaluate his actions and how he has interacted with Harry. Dumbledore might be shocked at first, since he probably thought Harry was on the same page as him most of the time.
The relationship turns into one of opposition in some fanfics. Harry, now independent, may be working towards goals that Dumbledore doesn't approve of. Dumbledore may see Harry as a loose cannon and try to control him from a distance, while Harry resents any such attempts. Their interactions become tense and full of unspoken accusations.
The fanfiction might show a more adversarial relationship. Harry could start to oppose Dumbledore's plans instead of following them blindly. This is very different from the original where Harry was mostly compliant. For example, in the original, Harry accepted Dumbledore's tasks like finding the Horcruxes, but in the fanfiction, he might question the motives behind these tasks and resist them.
He might give Harry detention. Harry could be made to clean the trophies in the trophy room or help Hagrid with some difficult tasks in the Forbidden Forest under strict supervision.