One possible plot could be Percy trying to hide his cancer from his friends at Camp Half - Blood at first. He doesn't want them to worry or think he's weak. But as the symptoms get worse, he has to tell them. Then they all band together to try and find a cure, whether it's through mortal medicine or some magical demigod - related remedy.
One possible plotline could be Percy's journey of dealing with the diagnosis. He might initially be in denial, then gradually accept it and start treatments. Another could be how his friends and family react, like his friends rallying around him to keep his spirits up.
One possible plot could be Percy getting drunk and accidentally revealing his true feelings to a friend or love interest. For example, he might finally admit his long - hidden admiration for Annabeth while in a drunken state.
One possible plot could be that Percy is targeted by a group of jealous rivals. Maybe they envy his status or abilities in the story's world. They might ambush him in a secluded place like an alleyway near his school or in a forest he often visits.
In this type of fanfiction, it could be that Annabeth enslaves Percy as a form of protection. She may think that by controlling him, she can keep him out of more dangerous situations. However, this backfires as Percy begins to resent her for taking away his freedom. It could also be part of a complex relationship dynamic where misunderstandings and past traumas lead Annabeth to believe that enslaving Percy is the only way to keep their relationship intact, although this is a very twisted view.
One possible plot could be that the demigods use their powers to prevent the school shooting. For example, Percy might control the water in the school's plumbing system to stop the shooter. Another could be that the shooting is part of a plot by a mythical monster, and the demigods have to figure out how to stop both the monster and the shooter. Maybe a magical object is causing people to go crazy and start the shooting, and the characters have to find and destroy it.
If Percy Jackson gets cancer in a fanfiction, it could completely change the nature of his adventures. His physical strength, which is crucial in the original stories, would be severely compromised. He might not be able to fight monsters as effectively. For example, he may struggle to hold his sword or run from danger. This could lead to new alliances, like relying more on his friends like Annabeth for physical protection while he uses his wits.
Maybe Percy is cursed by a powerful god or goddess who is angry with him. The curse causes his life force to slowly ebb away. His demigod powers start to fade too. His friends notice strange things like his sword not being as effective in battle and his ability to control water weakening. They then go on a quest to find the source of the curse and break it.
One great 'Percy Jackson cancer fanfiction' could be the one where Percy has to deal with a friend having cancer. It shows his loyalty as he tries to find a way to use his demigod powers to help. Maybe he goes on a quest to find a magical cure.
One possible scenario could be Percy being disowned because of his powers being seen as too dangerous. Maybe the other demigods or even his own family in the fanfic fear what he can do and decide to cut ties.
Well, perhaps he could die sacrificing himself to save his friends from some ultimate evil. Then, his rebirth could be linked to a powerful ancient magic. Maybe a forgotten god decides to bring him back for some grand purpose, like to stop a new threat emerging in the world of the gods.