It could also be a way to show his emotional state. He might be so deeply affected by a situation, like the loss of a dear friend or a major setback in his fight against the dark forces, that he is unable to speak. His silence then becomes a powerful way to convey his inner turmoil without using words.
Perhaps it's a plot device to shift the focus. If Harry Potter stops talking, the other characters around him will have to step up and communicate more. This can change the dynamics of the story, allowing other characters to develop further. For example, Hermione might take on more of a leadership role in communication when Harry is silent.
One possible reason could be that the author wants to create a sense of mystery. By making Harry Potter stop talking, it makes the readers wonder what he is thinking or feeling, and adds an air of enigma to his character. Maybe he has witnessed something so shocking that he is rendered speechless for a while.
One possible reason could be a misunderstanding. Maybe Hermione does something that Harry misinterprets, like siding with someone he doesn't trust in a Hogwarts issue. Another reason might be jealousy. If Hermione starts getting closer to another character, Harry could feel left out and stop talking to her. Or perhaps a dark influence affects Harry's mind, making him think Hermione is a threat to him in some way.
One possible reason could be that he has been through so much in his original adventures that he's just tired. He might feel like he's constantly being put in new, often contrived, situations in the fanfiction and he simply wants to step away from all the chaos and drama.
One possible reason could be a misunderstanding. Maybe Sakura said something that Naruto misinterpreted as being hurtful or dismissive of his feelings. For example, if she made a comment about his abilities in a negative way during a crucial moment, it could lead to him distancing himself.
Perhaps the writer of the fanfiction is trying to create a different character arc for Harry. Maybe he has faced so many hardships that he becomes disillusioned. For example, if he has lost too many loved ones and feels that his efforts are in vain, he might stop trying. It's a way to add a new layer of depth to his character.
Perhaps Harry has grown tired of always following Dumbledore's instructions without fully understanding the reasons behind them. He might want to make his own decisions and take control of his own destiny, rather than relying on Dumbledore all the time.
One reason could be that he discovers a new threat and decides he can't stay with the Dursleys any longer for their safety. Another might be that he simply can't bear their mistreatment anymore and finds an opportunity to escape.
The 'Harry Potter' series is far from being a 'criminal fanfiction'. J.K. Rowling created a magical universe filled with positive values. Harry and his friends are constantly fighting against the real criminals in the story, like Voldemort and his Death Eaters. It's a story about good triumphing over evil, not about criminality.
The writer can use body language. For instance, they can describe how Harry's eyes look downcast, his shoulders slump, and he just shakes his head slightly instead of speaking. This non - verbal communication can show that he has chosen not to talk.
One possible reason could be a powerful spell backfiring on him. In fanfiction, authors often play around with magic going wrong. Another reason might be extreme emotional distress. For example, if he discovers something truly shocking about his past or his friends.
One possible reason could be that Naruto has faced so many betrayals and hardships in the fanfiction. For example, if his friends turned on him for some contrived reasons, it might lead him to stop caring. Another reason could be the constant failure in achieving his goals, like protecting the village but always being undermined by political intrigue within the fan - made story.