One possible reason for Percy's headache in fanfiction is that he's been exposed to a very loud or irritating noise or sound. It could be a magical siren or just the chaos of a battle. Additionally, he might be dehydrated, which can easily cause headaches. And if he's had a head injury, that would obviously lead to a headache as well.
Well, it could be due to stress. Maybe he's facing a lot of pressure in the fanfiction world, like dealing with a difficult quest or some complex relationships. Another reason might be that he's overusing his powers, if he has any special abilities in the story. It could also be something as simple as not getting enough sleep.
In fanfiction, Percy might have a headache because of a magical or supernatural influence. For example, he could have been cursed. Or perhaps he's in an environment filled with some sort of noxious magical energy. Also, it could be a side effect of a potion he drank or a spell that backfired on him.
Another possible reason for getting a headache for the first time could be changes in diet. For example, consuming too much caffeine or alcohol in a short period can affect the blood vessels in the brain and cause a headache. Also, exposure to strong smells or bright lights suddenly might be a trigger.
It could be due to dehydration. If you haven't drunk enough water, your body can react with a headache. Another common cause is stress. When you're overly stressed, your muscles tense up, including those in your head and neck, leading to pain.
Perhaps in the fanfiction world, Bella caught a mysterious disease that's specific to that fictional universe. It could also be that she overexerted herself, like using her special powers too much if she has any in the story. Stress can also be a factor. If she's been through a lot of emotional turmoil, like a fight with a loved one or facing a big threat, her body might react with a fever.
A possible reason could be a magical transformation. For instance, he might encounter a powerful magical artifact that alters his appearance, giving him red eyes as a side - effect. This transformation could be a key part of a new adventure where he has to learn to control this new aspect of himself.
One popular Percy headache fanfiction might be one where Percy's headache is caused by some new and mysterious magical force in his world. It could lead to an adventure where he has to figure out the source to stop the pain.
A theme that often comes up is self - discovery. The headaches might be a sign of something new within Percy, like a new power or a connection to an ancient force. In these fanfictions, he has to figure out what this new aspect of himself is. Also, friendship is a big theme. His friends are usually there to support him through the tough times of having these headaches.
It could also be a form of self - discipline. Harry might want to prove himself to be more in control. So, he decides to follow a strict diet, avoiding the junk - like magical candies and over - indulgent magical feasts.
A common reason could be a curse. Some dark wizard might have cursed Harry, and the fangs are a visible manifestation of that curse.
In some fanfictions, Annabeth could abandon Percy because of a prophecy. If the prophecy seems to imply that being with Percy will lead to a great disaster, she might choose to leave to protect him or the world. Also, it could be due to a personal growth arc for Annabeth. She may realize that she has been too dependent on Percy in the past and decides to go off on her own to find her true self, leaving Percy behind.
One reason could be that he feels a sense of being out of place. Maybe new campers have come in and he no longer feels as important or needed. He might also leave in search of a greater purpose. In some fanfictions, he could be on a quest to find something that he believes is crucial for the safety of the camp, but he has to leave the camp itself to do it.