Well, one possibility is that Percy's friends try to find a cure. Maybe Annabeth uses her wisdom to research in the library of Camp Half - Blood while Grover tries to use his nature - related powers to find some special herbs. And Percy is just lying in his cabin, feeling really weak and feverish.
Obviously, Percy would be the main character as the story is about him getting sick. But his friends like Annabeth and Grover would also be important characters. They would be the ones trying to help Percy get better, so they play a big part in the fanfiction.
Annabeth would probably be very worried and take charge. She'd start researching immediately, looking through books in the camp library to find a cure. Grover would be constantly by Percy's side, using his nature - related powers to try and make Percy more comfortable, like bringing in fresh air and plants to help him feel better.
In addition to his family and friends, the medical ninja in the village would be involved. They would be the ones to accurately diagnose Boruto's condition. Shizune, for example, could come and check on him, using her vast medical knowledge. And the other young medical ninjas might learn from this case, as Boruto's illness could be something new or unusual, so they would be eager to assist and gain experience while taking care of him.
It could be a jealous demigod. Maybe someone who has always been envious of Percy's popularity and abilities. Now that Percy has wings, this demigod sees it as an opportunity to make Percy look bad. They spread rumors that Percy's wings are a sign of him being cursed by the gods and try to turn other demigods against him while he's already feeling sick and struggling with his new wings.
In this kind of fanfiction, one scenario could be that Will Solace uses his healing powers to try and cure Percy. He might be really worried as Percy is not only his friend but also someone he cares about deeply. Maybe he brings Percy to the infirmary in Camp Half - Blood and stays by his side, constantly checking on his condition and using his medical knowledge and powers to make Percy better.
In the 'Boruto Gets Sick' fanfiction, Boruto might experience various symptoms like a high fever, weakness, and coughing. His friends and family would likely be worried about him. They would probably take care of him, bring him medicine and try to make him comfortable.
Seth could be the one to help her. As her brother, he would be very concerned and might use his own knowledge of Fablehaven and its secrets to try and find a cure. He could also enlist the help of some of the friendly magical creatures they've befriended, like the fairies or the satyrs.
His teammates, Sasuke and Sakura, would surely be involved. Sasuke, although he may not show it as much, still cares about Naruto. He would keep an eye on Naruto's condition, and if there was any sign of danger, he would be ready to protect him. Sakura would be more hands - on with the medical care, checking his temperature, giving him medicine, and making sure he rests properly.
Sango could also take care of Kagome. As a strong and kind - hearted woman, she would know how to nurse Kagome back to health. She might use her knowledge of herbs and remedies to make Kagome feel better. Plus, she would offer emotional support to Kagome during her illness.