One reason could be for the sake of creativity. By changing Harry's hair color to red, it can open up new storylines. For instance, it could create a connection with the Weasley family in a different way. Maybe Harry would be more involved with their family traditions or be mistaken for a long - lost Weasley relative. Also, it can change the dynamics of his relationships. His enemies might not recognize him as easily, and his friends could have new inside jokes related to his new look.
Some writers might do it to explore the idea of genetics and upbringing. Since Lily was Harry's mother, there could be a latent part of her in him. Writers may want to dig deeper into how that could manifest in his actions and decisions. For example, if Lily was known for her quick thinking in dangerous situations, the fanfiction could explore Harry having a similar ability that was previously not emphasized in the original story. This gives the writer a chance to expand on the existing lore and create more complex and interesting plotlines.
Some writers do it for fun. It can be a hilarious way to show the characters' reactions.
Some writers do it because they want to create a more edgy or different take on the story. They might think that by making Molly a less - than - perfect character, they can add more conflict to their fanfic.
Some fanfic writers make Harry use dark magic to explore different character arcs. It's a way to break the traditional image of Harry as the pure - hearted hero. By having him use dark magic, they can show a more complex and morally ambiguous side of him.
Some writers might do it for shock value or to stand out, not realizing the negative impact. Also, a lack of awareness about gender equality issues could be a factor.
Fanfiction writers make it believable by showing the reactions of the other characters. If Hermione is researching frantically, and the doctors in the wizarding world are stumped, it gives the impression that this is a serious and real situation. Also, by making Harry's character arc focus on his acceptance of his fate, it mirrors what many real - life cancer patients go through, which helps the reader believe in the story.
It might be for the sake of shipping. If a writer wants to create a certain romantic or platonic relationship that they think would be interesting, having Naruto act like Sasuke can change the dynamics in a way that makes that relationship more plausible or exciting. For example, in a story where a character is in love with Sasuke - like qualities, Naruto taking on those qualities can add a whole new layer to the relationship.
Some writers simply drop in words from the existing Harry Potter languages like spells or the names of magical objects. For example, they might use 'Accio' when a character needs to summon something. Others might create new phrases within the language framework. They could make up a new incantation for a made - up spell.
Well, in some fanfictions, Dumbledore is bashed because writers want to explore alternative storylines. They might believe that Dumbledore was too controlling. He made a lot of decisions for Harry without really consulting him. So by bashing him, they can create scenarios where other characters step up or Harry has a different kind of growth without Dumbledore's influence.
A possible justification could be a deep exploration of Harry's post - traumatic stress. Writers might think that after years of fighting and losing so many people, Harry could reach a breaking point. But really, the Harry Potter we know from the books has a strong will and a support system that should prevent such a tragic end. So, these justifications seem more like attempts to create shock value rather than staying true to the character's nature.