A great plot could involve Percy being sent on a mission into the heart of chaos itself. Along the way, he discovers secrets about his own connection to chaos that he never knew. This could lead to him having to make some difficult choices between his loyalty to his friends and this new chaotic power within him. He might also encounter versions of his friends that have been corrupted by chaos, and he has to find a way to save them.
Perhaps Percy is caught in a time - loop within the chaos realm. Every time he tries to break free, he ends up back at the beginning of a terrible event. He has to figure out what is causing the loop and how to stop it. This could involve him exploring different areas of the chaos realm that he has never been to before, and meeting strange creatures that can help or hinder his progress.
One idea could be Percy having to face a new type of chaos monster that is immune to his usual powers. He would have to find a way to adapt and use his wits more than his strength. Maybe he teams up with an unexpected ally from the realm of chaos.
In a Percy Jackson Warrior of Olympus fanfiction, a great plot could involve Percy being sent into the future of the demigod world. He sees the consequences of the current actions of the gods and demigods. For example, he discovers that a war between the different pantheons has led to the destruction of many demigod camps. So, he has to go back in time and try to change the events that lead to this future. This would involve him having to convince not only his friends but also the gods to change their ways, which would be no easy feat as the gods are often stubborn. He might also meet some of his descendants in the future, and they could help him understand what exactly went wrong.
One idea could be exploring the backstory of the forgotten warrior more in - depth. Maybe they were once a great hero in a forgotten era of the Percy Jackson universe and got lost in time somehow. Another could be that the forgotten warrior has a special power that is now needed to defeat a new, emerging threat. They could be a key to unlocking an ancient prophecy that no one has understood until now.
One idea could be that Percy discovers a hidden power within himself that makes him an even more powerful immortal warrior. Maybe he can control time briefly, allowing him to outmaneuver his enemies in battles. Another could be that he teams up with an ancient immortal warrior from a different mythology, like a Valkyrie from Norse mythology, and they have to combine their powers to defeat a new threat to the world of demigods. And perhaps there's a prophecy that only an immortal Percy can fulfill, which involves traveling to the Underworld and making a deal with Hades to gain an ultimate weapon.
One idea could be that Percy discovers a hidden power within himself that is related to the concept of a timeless warrior. Maybe he can time - travel in a unique way to different eras of Greek mythology and has to battle ancient evils that are starting to resurface in the modern world.
One idea could be Percy using his skills in a chaotic new world filled with strange mythical creatures that no one has ever seen before. He has to navigate through this chaos and find a way to bring order to this new part of the mythical realm.
One idea could be that Percy discovers a hidden connection to Chaos while on a quest. Maybe he stumbles upon an ancient artifact that has the power of Chaos within it, and it starts to change him in unexpected ways. For example, he might gain new powers that are related to the primordial chaos, like the ability to manipulate energy in a more chaotic and unpredictable form.
One idea could be Percy discovers new powers as the Host of Chaos and has to learn to control them while facing an ancient enemy that was sealed away long ago. He could struggle with the chaotic nature of his new abilities and how they affect his relationships with his friends at Camp Half - Blood.
One idea could be Percy facing a new type of monster that is immune to water. This would really challenge his typical combat style. Another could be Percy having to team up with an old enemy to defeat a greater threat that endangers both the mortal and demigod worlds. Maybe he has to journey to a completely unknown realm within the Chaos to retrieve a powerful artifact that is the key to saving his friends.
One idea could be Percy discovering his new role as the Father of Chaos gradually. Maybe he starts having strange dreams or powers that he can't explain at first. For example, he might accidentally create small chaos portals without realizing it. Another plot could involve Percy having to deal with the other gods' reactions. Some would be fearful, while others might see it as an opportunity to gain power through him.
One idea could be Percy losing the Blades of Chaos and having to go on a quest to retrieve them from a powerful new enemy. Maybe a dark sorcerer has stolen them to use in a ritual that would bring chaos to the mortal and demigod worlds.