It can greatly affect the plot. For instance, if Harry is female, the way Voldemort views her could be different. He might underestimate her in some ways or be more intrigued by her. This could change the sequence of their confrontations. Also, if Hermione is male, his friendship with Ron and Harry could have new tensions. Maybe he'd be more competitive with Harry, which could lead to different sub - plots within the story.
It can make the plot more complex. For example, if Hermione was male, his relationship with female Harry could be seen as a potential romantic one earlier on, changing the love triangle aspect. Also, a male Hermione might approach academic challenges differently. The overall power dynamics in the wizarding world could shift. Male characters might not be as dominant in certain areas as they were in the original story.
His quitting potions could open up new storylines. He might have more time to explore other areas of magic or get involved in different adventures. For example, he could start an independent study of a unique form of magic that was not possible when he was occupied with potions. This can add more variety to the fanfiction plot.
It can completely change the direction of the plot. For instance, if Harry absorbs the Horcrux early on, he may have to face different challenges than in the original story. He might become a target for both sides, as the good side could be wary of his new, Horcrux - influenced state, and the bad side might see him as a threat to Voldemort's power.
It can greatly change the plot. If Harry has a different name, like Ethan, for example, Voldemort might not target him as easily. This could delay the start of the main conflict in the story. Or, it could cause the Order of Phoenix to be more cautious in approaching him as they may not be sure if he's the 'Chosen One' with this new identity.
If the sister has a romantic relationship with one of the characters, it can add a whole new dimension to the plot. Love triangles can form, causing jealousy and tension among the characters. This can also drive character development as they have to navigate their feelings while dealing with the greater threats in the wizarding world, like the ever - present danger of the Death Eaters.
Some fans might be very disappointed as Ginny and Harry had a much - loved relationship in the original books. It could lead to a lot of debate within the community, with some fans strongly against such a plotline and others being more open to exploring different and darker aspects of relationships.
It can make the story more intense. A pissed - off Harry Potter is likely to take more drastic actions. For instance, he might be more aggressive in his fight against the dark forces, which can drive the plot forward quickly.
Well, it can completely change the story arc. Since Harry is a central figure, if he's uncaring, the whole fight against Voldemort could be affected. He may not be as motivated to seek out Horcruxes or train for battles.
Another aspect is the friendships. Hermione and a female Harry might have a different kind of friendship. They could bond over more female - centric experiences, like dealing with the boys at Hogwarts in a different way. And Ron's relationship with a female Harry could also be different, perhaps more protective or having a different dynamic altogether, which would then ripple through the entire plot of the story.
It can create a lot of drama. For instance, it can lead to a rift between Harry and Ginny's friends who might be on different sides. Some friends might side with Ginny, thinking she has valid reasons for the rejection, while others might support Harry and try to get them back together.