Maybe in the fanfiction, Percy's death is a self - imposed sacrifice to save a loved one from a powerful curse. His friends then struggle with the guilt and the responsibility of carrying on his legacy. They might try to find a way to bring him back while also dealing with the political and social unrest that his death has caused in the world.
One possible plotline could be that Percy's sacrifice leads to a new era of peace in the fictional world. His death might inspire the other characters to come together and fight against the common enemies more fiercely. For example, his friends could form a stronger alliance to protect the world he gave his life for.
It could be that Percy's death is part of a grand prophecy. His death sets in motion a series of events that were foretold long ago. The other characters have to figure out how to navigate these events without him. Some might believe that his death was in vain at first, but later discover that it was a necessary step for the greater good of all.
One possible plotline could be that Percy sacrifices himself to save Artemis from a powerful and ancient enemy. Maybe there's a prophecy that foretells his death in order to protect her. Another could be that Percy is tricked into a situation where he has to give his life for Artemis to prevent a great disaster from befalling the world of the gods. And perhaps in his death, he becomes a symbol of heroism that changes the way the gods view demigods.
Another plotline could be that Percy's reincarnation is part of a grand plan. There could be a powerful being or a prophecy that dictates his reincarnation. When he is reborn, he is fated to either save or destroy this new world he is in. Along the way, he meets friends from his past life who have also been reincarnated, but they don't recognize each other at first, and they have to go through a series of adventures together to remember who they really are.
One possible plotline could be Percy's journey of grief and how he copes with the loss. He might become more withdrawn at first, then gradually find strength in his friends and his quest. Another could be his search for a way to bring his mom back, perhaps delving into dangerous magic or making deals with powerful beings. Maybe he also has to face the fact that his mom's death was part of a larger plan by the villains and he has to stop them from achieving their ultimate goal.
One possible plotline could be that Percy discovers his so - called friends have been secretly working against him all along. Maybe they spread false rumors about him, which makes everyone in his world turn against him. He then has to go on a journey alone to clear his name.
Maybe in the fanfiction, Naruto dies due to an incurable disease. Hinata is heartbroken. She starts to isolate herself at first. But then, remembering Naruto's unwavering spirit, she decides to get involved in the village's affairs more actively, especially in areas that Naruto was passionate about, like helping the orphans. And she might also try to find a way to bring back Naruto, perhaps through some ancient jutsu that she discovers.
One possible plotline could be that Kakashi is in a life - threatening situation during a battle against a powerful enemy. Naruto, seeing no other way to save him, uses a powerful and self - sacrificing jutsu that costs him his life. Another plotline might involve Naruto making a deal with some dark force to save Kakashi, but the price is his own life. Or perhaps in a mission gone wrong, Naruto takes a fatal blow meant for Kakashi.
Family members, if he has any in the fanfiction world, would be devastated. His mother, for instance, would have to deal with the loss of her son. She might become more involved in the affairs of the demigod world, trying to make sure that her son's sacrifice was not in vain. Also, his half - siblings, if any, would be affected. They could be inspired to step up and prove themselves worthy of Percy's sacrifice.
One possible scenario could be that Percy sacrifices himself to save Annabeth from a powerful and deadly monster. Maybe a huge and ancient sea creature that only Percy can hold off long enough for Annabeth to escape, but at the cost of his own life.
One possible scenario could be that Percy is overpowered by the various monsters in Tartarus. Maybe the sheer number of foes like the giants or the more terrifying creatures there are too much for him to handle, leading to his death.
A possible plotline could be Percy being assigned to a top - secret mission by Shield. He has to use his unique skills to infiltrate an enemy organization. Another plotline might be that Percy discovers a conspiracy within Shield itself and has to decide who to trust while trying to expose it.