If Percy Jackson joined Kronos in a fanfic, the story would change drastically. Firstly, the power balance would shift in Kronos' favor. Percy is a very powerful demigod, and his skills and abilities would now be used against the Olympians and his former friends. The demigod community would be in chaos. His friends would be heartbroken and confused, and they would have to decide whether to try to save Percy or just focus on stopping Kronos. Also, the Olympians would likely view Percy as a major threat and might take more extreme measures against him and those associated with him.
The story would transform into a complex tale of betrayal and moral ambiguity. Percy joining Kronos means the traditional good - vs - evil dynamic is disrupted. His friends would no longer be able to trust him blindly. The Olympians would be in a state of panic, as Percy knows many of their secrets. Kronos, on the other hand, would use Percy to his full potential, perhaps sending him on missions to undermine the Olympians from within. This would also affect the relationships between the different demigod camps. Some might side with Percy, believing in his new cause, while others would firmly oppose him. The fanfic could explore how Percy's actions would ripple through the entire demigod world, causing upheaval and changing the fates of many characters.
Percy would likely become more conflicted. His previous identity as the son of Poseidon shaped his values and actions. But as the son of Kronos and Rhea, he'd have to reevaluate everything. He might become more cautious, as he now represents a more controversial lineage.
The relationship with Poseidon would be extremely complicated. Poseidon would be torn between his love for Percy and his fear of what Percy could become as Kronos' twin. He might try to distance himself from Percy at first, which would deeply hurt Percy. On the other hand, Percy's relationship with some of the minor gods might improve. Since they are often overlooked by the major gods, they might see Percy as a potential ally in changing the status quo. Percy's relationship with Luke, if he were still alive in this fanfiction, would also be interesting. Luke might try to use Percy's connection to Kronos to his advantage, but Percy would have to be careful not to be manipulated by Luke.
If Percy becomes influenced by Kronos in this fanfiction, his sense of morality would be greatly affected. He would probably lose his sense of right and wrong which was a big part of his character before. His loyalty towards Camp Half - Blood and his friends would be in jeopardy. He might start to think that the ends justify the means, which is a very Kronos - like way of thinking. And he could become more aggressive and less patient, as Kronos was always in a hurry to regain his power and rule over the world.
One possible plotline could be Percy struggling to control Kronos' influence. He might have to fight against Kronos' will to take over his body completely while trying to keep his friends safe.
Well, it would probably have a lot more pirate elements. Instead of going on quests related to Greek mythology, Percy might be sailing the seas looking for treasure like Jack Sparrow. The demigods might become more like pirates, with their own ships and crews.
Their relationship could start with Kronos trying to manipulate the female Percy. But as she gets to know him through their interactions (maybe in dreams or through some magical connection), she starts to understand his motives, which were once noble but got corrupted. She might then try to reform him.
His character could develop in a way that he becomes more powerful. Since Kronos is a very powerful being, Percy might inherit some latent power. But he would have to learn to control it. He would also become more empathetic towards the Titans in a sense, as he realizes that Kronos is his brother. This could lead to him trying to find a middle ground between the Titans and the gods, which would be a major shift in his character from just being a defender of the gods.
The character development of Kronos is also important. Fanfic writers often explore his past and what led him to become the villain he is. They might give him more complex motives, like a desire for revenge that goes beyond just power. Also, the relationships between the characters, like Percy's relationship with his friends in the face of Kronos' threat, are key elements. In some fanfics, these relationships are tested and strengthened in different ways.
His relationship with Annabeth would be very strained at first. She might be very suspicious of him and his motives, given his relation to Kronos. But as she sees Percy struggling against the dark influence, she could come to his side and help him. Their relationship would then become deeper as they face this new challenge together.
There are a few reasons why Kronos would be interested in reading Percy Jackson fanfiction. One is that he wants to see how the demi - gods are being depicted in these fan - made stories. Since they are his foes, any new information or different portrayals of them could be valuable to him. Another reason is that the fanfiction world might show him new ways to manipulate or interact with the world of the gods and mortals. It could also be that he simply enjoys seeing the creativity of mortals when it comes to his own story and the world he knows so well.