His friends would most likely be very concerned. They would probably bring him things like food and medicine. TK might pray for his quick recovery.
When Ken gets sick in the fanfiction, his friends' reactions would vary. Davis, being the head - strong one, would initially be a bit over - eager in trying to help, but his heart would be in the right place. Yolei, with her nurturing side, would be like a mother hen, constantly checking on Ken's condition. TK, having a more empathetic nature, would be there to listen to Ken if he wanted to talk about how he was feeling. Cody, on the other hand, would be very methodical in his approach, making sure all the practical aspects of Ken's care were taken care of, such as ensuring he has a clean and comfortable place to rest.
Raven would probably be the first to sense that something was wrong with Beast Boy. She'd be quiet about it at first, but she'd start keeping a closer eye on him. Maybe she'd make him some herbal tea that she believes has healing properties.
Well, Betty will be super worried. She's always had a soft spot for Archie. She might skip her own activities to stay by his side, constantly checking his temperature and making sure he's comfortable. Jughead, on the other hand, will try to keep things light. He'll tell Archie stories about the latest strange things he's seen in Riverdale to distract him from his illness. Veronica will be more of the practical one. She'll call in doctors or specialists, using her family's influence to ensure Archie gets the best care possible. All in all, his friends will rally around him.
Olaf would try to make Anna laugh. He would tell his silly jokes and do his goofy dances. He would also try to keep Anna warm with his carrot nose. He might even build a small snowman inside the room to keep Anna company when everyone else is busy.
Well, if Ken gets sick in a fanfiction, it could lead to some character development. Ken has had a complex past in the Digimon series. This sickness could be a time for him to reflect on his actions. Also, it might show a more vulnerable side of him to the other characters. His friends could learn more about his true self as they take care of him during his illness.
In most 'Naruto gets sick' fanfics, his friends are very concerned. For example, Sakura will immediately start using her medical skills to diagnose and treat him. Sasuke, although he may not show it outwardly as much, will stay by Naruto's side and keep a watchful eye. Shikamaru might come up with plans to make Naruto more comfortable during his illness. And Hinata, she would be really worried and would probably bring Naruto some home - cooked food to help him regain his strength.
Sakura would probably be the first to jump into action. As a medical ninja, she would immediately start examining Naruto to figure out what's wrong. She might be worried but also determined to find a cure.
Yamamoto would be more level - headed. He would first try to find out the details of Tsuna's arrest. He might talk to the police or other authorities to see if there's been a misunderstanding. He'd also be a source of support for Tsuna's family during this tough time.
His friends would most likely be very worried. They would gather around him, trying to figure out what was wrong. Percy might use his water powers to cool Leo down if he had a fever. Annabeth would be researching in the library, looking for any information on demigod illnesses. Hazel could use her powers to sense if there was any dark magic involved in Leo's sickness.
His other friends like Shikamaru would think of the most practical solutions. He might calculate the risks of continuing the mission with a sick Naruto and come up with a plan. Maybe he'd suggest splitting the group, with some staying to take care of Naruto and others proceeding with the mission - related tasks that can't be postponed.
Fishlegs would be really concerned and would use his knowledge to try and help. He might look for herbs or remedies that could aid in Hiccup's recovery. Snotlout, on the other hand, might initially try to act tough but deep down he'd be just as worried. He might try to show off his strength by helping to carry Hiccup or something like that. And Tuffnut and Ruffnut would be their usual chaotic selves, but also very caring towards Hiccup in their own unique way. They could make jokes to try and cheer him up while he's in pain.