One way is to give them limitations. In a school shooting situation, their powers might be affected by the modern environment. For instance, if there are metal detectors in the school, Percy might not be able to bring his sword in easily. So he has to rely on his other skills. Also, the characters can be involved in the pre - shooting events. Maybe they notice some strange behavior in a student who could be the potential shooter. They try to investigate in a way that normal students might, like reporting it to the school counselor, but also use their demigod intuition to dig deeper. This shows a more realistic integration of the Percy Jackson characters into the school shooting fanfiction scenario.
In fanfiction, when Percy is injured, it's important to consider the details of the injury. If it's a magical injury, what are the side effects? How does it affect his powers? For instance, if he has a wound from a poisoned weapon, he might have hallucinations or weakness. You should also show the process of his recovery, whether it's slow and filled with setbacks or quicker due to some special treatment. All these elements combined can create a very realistic portrayal of an injured Percy Jackson in fanfiction.
In some Percy Jackson fanfictions, Excalibur might be incorporated as a powerful weapon that finds its way into the hands of a demigod. It could be a plot device to add more power and mystery to the story.
The theme of social class in 'The Outsiders' can be used. In 'Percy Jackson' fanfiction, you could create different groups of demigods based on their parentage or abilities. There could be an 'outsider' group of demigods who are looked down upon, similar to how the Greasers were. Percy could then work to bridge the gap between these groups, just as he tries to unite different camps in the original series.
One way is to use the Percy Jackson characters' powers in an Abrahamic setting. For example, Percy's ability to control water could be seen as a gift from God in an Abrahamic fanfiction. Another way is to have the Percy Jackson characters interact with Abrahamic figures. Like Percy meeting an angel and having a conversation about the nature of the world.
It could be shown through gradual changes in behavior. For example, a character under mind control might start to be more withdrawn or overly aggressive in a way that's not normal for them. Their speech might also change, becoming more robotic or repetitive.
One way could be by making him a mysterious new demigod. He could have his Sharingan ability which might be related to some special power in the Percy Jackson universe, like being able to see through the Mist more clearly than others.
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.
In a crossover fanfiction, the demon could be a result of some dark magic experiment gone wrong that combines the elements of both universes. For example, a sorcerer in the Percy Jackson world tries to use a spell from the Book of the Damned (from Supernatural) and accidentally creates a super - powerful demon. Percy and his friends, along with the Supernatural hunters, would then have to figure out how to stop it. This would involve the demigods using their unique powers like controlling water or flying, while the hunters use their knowledge of exorcisms and demon lore.
In the fanfiction, the 'ocean eyes' could be linked to a lost underwater civilization. A character with 'ocean eyes' might start having visions of this civilization through their eyes. These visions could guide them and their friends on a quest to find this lost place. Along the way, they would face various challenges and enemies, all while trying to figure out the significance of the 'ocean eyes' and the lost civilization.
They can be used as a MacGuffin. The characters could be searching for a special monofilament wire that has unique properties, like being able to cut through any material or having the power to nullify magic. This search could drive the plot forward as the characters face various challenges and enemies while trying to obtain it.