Percy is the son of Arthur. Like the other children of Fates, Percy was placed in the Deeprealms to protect him from the war. Arthur did not want Percy to be lonely in his Deeprealm so he found him a wyvern to keep him company and Percy named him Ace. In his Paralogue, fed up with waiting for his father, Percy decides to disobey his father's order to stay in his Deeprealm and ride out of it on Ace, his wyvern. However, Arthur had come to his Deeprealm to visit his son but Percy is upset that he has not visited in a while. Percy labels him a villain and called a group of mercenaries to take him out. Arthur attempts to persuade them that Percy is his son, but they do not believe him because he made Percy cry and that he apparently resembles Gazak. Though Arthur continues to try and convince them of his identity, Percy comes in and coldly calls him Gazak, causing the mercenaries to attack him. After either scaring away or defeating all the mercenaries, Percy has a heart-to-heart conversation with his father where Arthur apologizes for not visiting more often. Arthur invites Percy to be his sidekick or perhaps allow him to be his sidekick. Though confused if that meant that Arthur would be staying in his Deeprealm, Arthur clarifies by allowing Percy to join the army if he wants to, an offer he readily accepts. Unfortunately, Ace nearly bites Arthur until Percy explains that he is now happy to be a duo of great justice with his father.