One possible plot could be Percy being chosen as the Horseman of Death due to some ancient prophecy. He might have to travel to the Underworld more often and deal with the spirits there in a new way. Maybe he has to collect the souls of those who are supposed to die but are being held back by dark magic.
Well, in this fanfiction, the plot could revolve around Percy's struggle with his new role as the Horseman of Death. He may face opposition from his friends who don't understand his new powers and duties. Also, he could be targeted by villains who want to use his connection to death for their own evil plans. For example, they might try to raise an army of the dead through him. He would then have to fight to protect his newfound role and the world from these threats.
In a Percy Jackson as Horseman of Death fanfiction, the story could start with Percy having strange dreams about death and the afterlife. These dreams could lead him to discover that he has been chosen as the Horseman of Death. As he begins to understand his new role, he realizes that it comes with great responsibility. He has to balance his normal life as a demigod with his new duties. He might encounter new mythical creatures related to death, like the Grim Reaper in a different form. His relationships with his friends at Camp Half - Blood would change as they fear his new powers at first. But eventually, they come to accept and support him as he battles against those who want to use the power of death for chaos and destruction.
Annabeth could be one of his main allies. She is smart and would help Percy understand the more complex aspects of his role as Horseman of Death. Grover might also be there for him, using his nature - related powers to help Percy in places where the power of death interacts with the natural world.
One possible plot could be that Percy is tricked into a deadly situation by a new villain who has the power to manipulate the elements. Percy is killed in a massive explosion. But his love for Annabeth and his loyalty to his friends are so strong that his soul doesn't pass on. Annabeth, using her intelligence and her knowledge of ancient magic, figures out a way to reach Percy in the in - between world. With the help of some friendly spirits, she brings Percy back to life, and they then set out to defeat the villain who caused his death.
Well, it could involve Percy facing numerous challenges in the underworld. Maybe he has to battle new and powerful monsters that guard the Doors of Death. He might also get some unexpected help from his friends, like Annabeth using her wisdom to figure out the secrets of closing the doors. And there could be a final showdown with some major villain who doesn't want the doors to be closed.
Nico di Angelo has a strong connection to the Underworld, so he's a prime candidate. He can already communicate with the dead and has some control over the shadows, which are related to death in a way. In fanfiction, he could be further developed to become the Master of Death, perhaps by making a deal with Hades or finding a hidden power within himself.
A great plot could be Percy being sent on a top - secret mission by the army. This mission could be related to some ancient artifact that has military applications but also ties to his demigod world. Along the way, he meets other demigods who are also in the military for various reasons. Together, they have to overcome not only military enemies but also mythical creatures that are after the same artifact.
Well, the plot might start with Percy being sent on a special mission by the gods. They need someone with his quick reflexes and sharp eyesight to be a sniper. Along the way, he has to deal with the moral implications of taking lives from a distance. He might also face challenges in terms of getting the right equipment and training. His friends could be initially skeptical of this new role for him, but as they see him succeed in various battles, they come to accept and rely on his sniper skills.
One possible plot could be Percy using his bike to travel across the country to find and protect other demigods. He could encounter various monsters along the way and use his biker skills, like sharp turns and high - speed maneuvers, to evade them.
One possible plot could be that a powerful enemy, let's say a dark sorcerer, has found a way to use the powers of the Greek gods against the supernatural beings in the Mikaelson universe. Percy Jackson is sent to investigate and ends up getting caught in the middle of the Mikaelson family drama. He has to use his skills as a demigod and his knowledge of Greek mythology to help the Mikaelsons defeat this new threat while also trying to keep his own identity and mission a secret from some of the more untrustworthy members of the family.
Maybe Percy Jackson somehow gets transported to the world of Stranger Things and has to fight the Demogorgon. He could use his water - controlling powers to try and defeat it, like dousing it with a powerful stream of water.
Well, in a 'Percy Jackson Endgame' fanfiction, the plot might involve Percy finally having to make a huge sacrifice to save not just the demigod world, but the entire mortal world as well. The other characters like Annabeth, Grover, and the rest of the gang would be trying to find an alternative solution while Percy is ready to give it all up. It could also include a race against time as some sort of dark prophecy looms over them.