Elsa and Anna are the most likely main characters. But we can't forget about Kristoff. He could be the one who uses his knowledge of the mountains and the outside world to search for a cure for Elsa. And Sven, his reindeer, could be his trusty sidekick in this search. So all of them could be main characters in this fanfiction.
Obviously Elsa herself would be one of the main characters since she is the one getting sick. Anna would also be a main character as she would be very concerned about Elsa's condition and would do everything she can to help. Olaf could also play an important role, using his cheerfulness to try to make Elsa feel better.
Anna would surely be the first to help Elsa. Anna has always been there for her sister, and when Elsa gets sick, she would do everything she could, like bringing her warm soups and staying by her side to keep her company.
Obviously, Bendy would be one of the main characters since he's the one getting sick. His friends like Boris and Alice would also be main characters as they would likely be involved in taking care of him or finding a cure.
Mario would most likely be a main character too. He's Luigi's brother, so he'd be there to take care of him or at least be really worried about him. Princess Peach could also be a main character. She might visit Luigi when he's sick and bring some kind of magical item that could potentially help him get better.
Obviously, Death the Kid himself would be the main character. He's the one who's sick after all.
In this 'jace gets sick fanfiction', Jace is the one who gets sick, of course. But there might also be his family members. For example, his mother could be a very important character, hovering over him, making sure he takes his medicine and gets enough rest. And perhaps there is a wise old doctor in the story, who tries different remedies to cure Jace.
His friends like Batman and Nightwing could be main characters. Batman might use his detective skills to figure out what's wrong with Robin, and Nightwing could be there to offer emotional support.
Since Rigby is sick, his family members could also be main characters in the fanfiction. They might come to visit him and bring their own unique family drama to the story. And his friends from the park, like Muscle Man and High Five Ghost, could also be involved, trying to cheer him up while he's ill.
Chica could also be a main character. She could be the one who tries to comfort Bonnie while he's sick. Maybe she brings him some virtual food or something to cheer him up. And Foxy might be another important character. He could be the one who goes on adventures to find a cure or a way to fix Bonnie. He's the more adventurous type, so it would make sense for him to be the one looking for solutions outside the normal areas in the pizzeria.
In this fanfiction, not only her immediate family and friends but also neighbors or classmates could be involved. Neighbors might offer help like bringing over some home - made remedies. Classmates could be concerned and send her get - well - soon cards or come to visit her after school. And if there are any pets in Ginny's life, they could also play a role, like staying close to her and providing some comfort.
Well, one possible plot could be that Elsa's sickness is a magical ailment. Maybe she got it from using too much of her ice powers at once. Her sister Anna would then be worried sick and try to find a cure. She could search all over Arendelle and even beyond for someone who can help Elsa get better.