There's also a fanfic where Percy is slowly dying from a mysterious poison. His friends are desperately trying to find a cure while Percy battles his own mortality. This one is really good at building tension and exploring the relationships between the characters as they face the possibility of losing Percy. It shows how much they rely on him and how hard they're willing to fight for him.
There are also endings where Percy's spirit lingers. He becomes like a guiding force for his friends, even in death. This can be really touching as his friends still feel his presence and are inspired by his memory to keep going and face whatever challenges come their way.
Annabeth would be completely devastated. She might go into a state of shock at first, not believing that Percy is really gone. Then she would be filled with anger and a determination to find a way to bring him back, if possible. She could start researching ancient magic or prophecies that might reverse his death.
One scenario could be Percy sacrificing himself to save his friends from a powerful and ancient evil. Maybe he faces off against a primordial being and uses his powers to hold it back long enough for his friends to escape, but at the cost of his own life.
One common theme could be the impact on his friends. For example, Annabeth might be devastated and go through a journey of grief and self - discovery. Another theme could be the effect on the demigod world. With Percy gone, there could be a power shift or a new threat emerging that the remaining demigods have to face without his leadership. Also, it might explore the idea of fate and whether his death was avoidable or part of some greater plan in the world of Greek mythology.
It completely changes the direction. In the original plot, Percy is a central figure in many battles and quests. His death would mean those quests are either left unfinished or have to be taken up by others. For example, if he was supposed to lead a battle against a major villain, now someone else has to step up. It also affects the relationships. His death could create rifts between characters who blame each other for not being able to save him.
Yes, in some Percy Jackson fanfics, he could be depicted as a Titan. Fanfic writers often take creative liberties and might come up with unique storylines where Percy has Titan - like qualities or is even reimagined as a Titan for the sake of an interesting plot twist.
A new, powerful demigod who is jealous of Percy's fame and power could be the villain. This demigod has discovered a dark spell that they use on Percy, causing him to slowly die. They want to take over Percy's position as the 'hero' among the demigods.
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.
He might meet other inter - galactic beings. For example, some sort of space - faring demigods from a far - off galaxy. Or he could encounter powerful entities that are the rulers of other planets.