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.
His character could change in terms of power. With the blood of Kronos and Rhea, he may gain new and more dangerous powers. This could lead to a sense of arrogance or a fear of using his powers wrongly. Emotionally, he might be more isolated as some would view him with suspicion due to his new parentage. He would have to struggle to prove that he is still the same Percy at heart, despite the new heritage.
Well, Percy's character would go through a major transformation. Initially, he would be shocked and confused about being the son of Kronos and Gaea. This would cause him to reevaluate his relationships with his friends and allies. He may feel isolated as he believes they might not accept him anymore. As he delves deeper into his heritage, he would learn about the history and motives of Kronos and Gaea. This knowledge would give him a different perspective on the world of gods. He would have to make tough decisions, like whether to use the powers associated with his parents for good or evil. Through these experiences, he would become a more self - aware and morally complex character, no longer simply the hero who always follows the Olympians' rules but someone who has to make his own path based on his understanding of his true identity.
One possible plot could be Percy's discovery of his true parentage as the son of Kronos and Rhea. This could lead to a huge power struggle within the demigod world. Other gods and demigods might fear his potential power and try to either eliminate him or recruit him to their side.
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.
To develop the character, start with his backstory. Since he's the son of Kronos, he might have grown up in a very different environment compared to other demigods. Maybe he was hidden away by a minor god who felt sorry for him. His past experiences of being alone and shunned because of his father would shape his personality, making him a bit of a loner at first.
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.
He'd probably be more aware of his appearance. Instead of just being a scruffy, normal - looking demigod, he might take more care in how he presents himself. He could also be more charming without really trying, which might get him into trouble sometimes as people might misinterpret his intentions.
Percy would likely become more studious. Since Athena values knowledge, he would be more interested in learning about history, magic, and other aspects of the demigod world. He might spend more time in the library at Camp Half - Blood, much to the surprise of his friends. His relationships with others would also change. He could be more aloof at first as he tries to adapt to his new role, but as he grows into it, he would form deeper, more intellectual connections with those around him.
One possible plot could be Percy's journey to discover his true identity as the son of Kronos and Rhea. He might face challenges from the other gods who fear his power. For example, Zeus could try to stop him from fully realizing his potential. Percy would also have to deal with his own internal struggle. He grew up believing he was Poseidon's son, so this new revelation would shake his world. He could start a quest to find out more about his parents' relationship and what it means for him in the grand scheme of the mythological world.
Well, in such a fanfiction, Percy's character arc would be completely transformed. Instead of having the connection to the sea like in the original where he's Poseidon's son, he might have a connection to time or something related to Kronos' powers. His relationships with other characters would also be different. For example, his friendship with Annabeth might be strained as she might see him as a threat due to his new 'parentage'. The story could be filled with internal struggles as Percy tries to come to terms with who he really is and the legacy of Kronos.
His relationship with Annabeth would be really strained. Annabeth is a firm believer in the gods, and if Percy is the son of Kronos, she would be very suspicious and probably feel betrayed. She might even try to fight Percy at first, thinking he's a threat to her and her friends.