It could be that he failed at something important like a difficult task or a competition within the story of the fanfic. This would surely make him feel down.
One possible reason could be a conflict with her friends. Maybe there was a misunderstanding during a quest, like her ideas were not taken seriously by the group. For example, she had a well - thought - out plan but others ignored it, which made her feel unappreciated and thus upset.
The bride might have chosen friends over family. Mom expected family loyalty in the wedding party selection. So, she's upset that the sister was overlooked.
The author can also use internal monologue. Let Harry think about all the things that are going wrong in his life in the fanfic. Thoughts like 'Why did this happen to me?' can effectively convey his upset state of mind. In addition, the author could also describe his tone of voice when he does speak, perhaps it's quiet and shaky, which is a sign of being upset.
Maybe the fanfiction portrays him in a negative light, like making him out to be a bad person or having him do things that are completely against his real - life values.
Maybe he got injured during a dangerous adventure. For example, he could have fallen from a great height while chasing a dark wizard and broken his legs.
Another possibility is that he discovers some dark secrets about his family or his past. These secrets could shatter his perception of himself and his loved ones. It could make him question everything he has known and believed in. For instance, if he finds out that his father was involved in some immoral deeds in the past, it would be a huge blow to him and result in his sadness.
One reason could be to create a new and different plot. By making Harry arrogant, the writer can show how his relationships with other characters change. For example, his friends might be less tolerant of him.
Well, perhaps in the fanfiction, the Order made decisions without consulting Harry. They might have put him in a dangerous situation without his knowledge, like sending him on a mission that seemed suicidal. It could also be that they were keeping secrets from him that he felt were important to his fight against Voldemort.
One possible reason could be differences in their personalities. Harry is often portrayed as more down - to - earth and Fleur as more haughty in the books. In fanfiction, this might be exaggerated, causing her to reject him. Maybe she doesn't like his fame either, as Harry is 'the Boy Who Lived' and always in the spotlight, which she might find tiresome.
In fanfiction, Harry Potter might be angry if his friends are in danger and no one seems to be taking it seriously. He's very protective of his friends, like Ron and Hermione. So if some authority figures in the story are being dismissive of the threats his friends face, that would surely make him angry.