One possible reason could be a spell gone wrong. Maybe a magician or a god accidentally casts a spell that sends Percy back in time.
Some fanfiction writers may do it to stand out. Since the Percy Jackson series is so well - known, creating a version where he is a devil can attract attention. Also, it could be a way to explore darker themes. The original series has a lot of heroic and positive elements, but in fanfiction, making Percy a devil allows for a look at the other side of the coin, like how his powers could be used for evil instead of good.
The entire world of the story could be altered. Monsters might be stronger or weaker depending on what he changes in the past. If he stops some key event that was related to a monster's origin, it could lead to a different power balance in the world of demigods.
One reason could be to create a more powerful version of Percy. Fanfiction writers might want to see how he would fare in more extreme situations with super - soldier abilities added to his demigod powers. It's also a way to mix different fictional universes and concepts, making the story more unique.
There are several possible reasons. Firstly, for the sake of drama. It makes for a very intense and emotional story when a beloved character like Percy dies. Secondly, it could be to explore the after - effects on the other characters. How would Annabeth cope? How would the Camp Half - Blood react? Also, it might be a way to show the unforgiving nature of Tartarus.
In fanfiction, Percy could become a champion of Kronos due to a complex web of factors. It could start with his disillusionment with the Olympians. After all the battles he's fought for them, if he sees no real change in how they treat demigods or the world in general, he might be open to an alternative. Kronos, being a master manipulator in these alternate stories, could offer Percy power and a chance to truly make a difference. Also, Percy's relationships could play a role. If someone he trusts sides with Kronos and convinces him, or if he's in a situation where he has no other allies and Kronos offers support, he could end up in that role. But these are all departures from his original character in the official Percy Jackson series.
One reason could be for a fresh take on the story. Writers might want to break away from the typical demigod narrative and explore a darker, more supernatural side of the Percy Jackson universe. Another reason could be to create a more complex and morally ambiguous character. By making him a demon, they can introduce new conflicts and relationships.
Well, in fanfiction, one reason could be the loss of his friends. Percy has been through so many battles, and if he loses someone close like Annabeth or Grover, it could send him into a deep depression. Another reason might be the burden of his prophecies. He's constantly expected to save the world, and that kind of pressure can wear a person down over time.
Perhaps Percy has proven his worth through his unwavering loyalty and courage. Loki, who is used to seeing self - serving and deceitful behavior among the gods and mortals, is impressed by Percy's pure - heartedness. His actions of always protecting his friends and standing up for what is right might make Loki feel that he is worthy of respect, leading to Loki bowing to him.
Maybe Percy unknowingly breaks some ancient and very strict laws of the Gods. For example, he might interfere with some sacred rituals or places that are off - limits to mortals, even demigods like him. In the fanfiction world, the Gods could be very unforgiving when it comes to such violations and decide to kill him as a result.
Maybe he faced an extremely powerful enemy that he couldn't overcome. It could be a new and terrifying monster created by the Titans or some other dark force.