Maybe it has something to do with an ancient magic. Some long - forgotten spell or charm might have been cast on Harry when he was a baby, like the protection charm his mother gave him. This magic could have given him the power to communicate with crows.
Perhaps it's a gift from a magical creature. There could be a powerful and wise crow or a group of crows that decided to bestow this ability on Harry. They might have seen something special in him, like his courage or his kind heart, and thought he could use this ability for good in the wizarding world.
Well, it could change the plot in many ways. For example, the crows might act as spies for Harry, giving him information about the Death Eaters' whereabouts. They could also help him find hidden objects or secret passages. Maybe they warn him of impending danger.
One possible reason could be his past experiences with some cruel adults, like the Dursleys. They treated him horribly, so in fanfiction, this trauma might make him generally fearful of adults. Another reason could be his experiences with certain authority figures at Hogwarts who may have been strict or unfair, which could be exaggerated in fanfiction to create a fear of adults.
In fanfiction, Harry could faint due to some sort of magical disease or curse. There could be a new, made - up illness that affects wizards and one of its symptoms is fainting. Or perhaps he's in a situation where he's cut off from his magic for a while and his body, which is so used to having magic, goes into shock and he faints. It could also be that he's in a place with really strange or strong magical energy that his body can't handle, and this causes him to pass out.
It could be due to some kind of self - sacrifice he made in a previous battle. For example, he might have used a very dangerous spell that had a side - effect of slowly killing him to save his friends or the wizarding world.
One possible reason could be that the author of the fanfiction is portraying him in a way that goes against his character. Harry is known for his integrity and if the fanfic makes him do unethical things, he might seem to'refuse to talk' in that narrative.
It could be a result of a magical spell gone wrong. Maybe he was experimenting with some powerful magic, and it had an unexpected side effect on his appearance, turning his hair long and white.
One reason could be that Harry is under an extreme amount of stress. He has so many burdens on his shoulders in the wizarding world, like fighting Voldemort. This stress could manifest physically as a seizure, especially if he is in a tense situation in front of Snape, who is often a source of anxiety for him. For example, if Snape is about to accuse him of something he didn't do while he is already worried about other threats to the wizarding world.
One reason could be to explore the darker side of human nature. Even though Harry is a hero in the original series, fanfiction writers might want to see how he would be affected if he was pushed to his limits. Another reason is to create a more complex and controversial storyline. It grabs readers' attention as it goes against the normal perception of Harry.
Some fanfiction writers may have a different vision for Harry Potter's character. They might see him as more of a diplomat or a healer within the wizarding world, rather than a fighter. So, they write stories that reflect this different view of the character, where he uses his wits and other skills rather than engaging in physical or magical combat.
One reason could be that the official Harry Potter canon is so extensive and detailed that it overshadows fanfiction. The original story has such a rich world, characters, and plotlines that it becomes the main focus for many fans, leaving less room for fan - created stories.