It completely flips it. Instead of being the hero we know, he becomes a figure of fear and suspicion. His actions would shock those who knew him, as he was always seen as the one to fight against the dark, not join it.
Well, it makes his character more complex. He is no longer just a one - dimensional hero. His betrayal shows that he might have had hidden desires or vulnerabilities all along. For instance, his decision to join the dark side could reveal that his anger or thirst for revenge was stronger than his sense of good, which was not something we considered much in the original story.
It changes the way we view his relationships too. His friends would be devastated, and they would start to question their own judgment. His betrayal could also cause a rift in the wizarding community, as people would wonder if they could ever really trust anyone again, since someone as 'good' as Harry could turn.
Perhaps he was deceived. There might be a powerful dark wizard who managed to convince Harry that the dark side had a more 'just' cause. This wizard could have used false information about the history of the wizarding world and how the dark side was initially misjudged.
The fanfiction makes Harry a much more complex character. He's no longer just the good - hearted boy we know. As the new Dark Lord, he might have internal struggles. Maybe part of him still remembers his old values, but the dark power within him is overpowering those. This makes him a more morally ambiguous character, rather than the straightforward hero we're used to. For instance, he could be conflicted when it comes to harming his old friends, but still be driven by the new - found dark desires.
The Ministry of Magic could be the ones to betray Harry. They might try to use Harry as a pawn in their political games, and when Harry realizes this, he loses faith in the so - called good side. Voldemort then takes advantage of Harry's disillusionment and convinces him to join.
Her character would likely become more ruthless. Since she's joining Voldemort, she'd have to adapt to his ways of using dark magic without hesitation. For example, she might no longer have the moral qualms about using the Unforgivable Curses.
The teachers at Hogwarts, like Dumbledore (if he were still alive in the fanfic), would be deeply concerned. Dumbledore always saw great potential in Harry for good. He would probably try to understand what led Harry to this path and would use all his wisdom and magic to try and turn Harry back. The other teachers would also be on high alert, fearing for the safety of the students and the future of the wizarding world.
Hermione could be the one. Maybe she gets jealous of Harry's fame and power, and starts spreading lies about him, which leads to his betrayal. As a result, Harry feels so hurt that he turns to Voldemort.
Well, in 'Dark Lord Harry Potter fanfic', the most obvious change is Harry's alignment. Instead of being the hero, he becomes the villain or at least an anti - hero. This completely flips the moral compass of the story.
It can mislead those who haven't read the original books. If someone reads only this fanfiction, they might get a wrong idea about Harry Potter being arrogant when he's not.
It makes him seem more out - of - the - ordinary. Instead of the typical heroic image, he appears more quirky.
The fanfic changes the perception of Dumbledore's character in that it shatters the image of his infallibility. He is no longer the perfect headmaster and guide. Stealing from Harry shows that he is capable of moral wrongs, and this can lead to a more nuanced understanding of his character, where he is not simply all - good or all - bad but a mix of both, with his own motives and desires that might not always align with what is best for Harry.