In some fanfictions, Percy might repress emotion by bottling up his thoughts. He could avoid talking about his feelings, like when he's faced with difficult situations or past traumas. For example, he might keep quiet about his fear during a dangerous quest instead of sharing it with his friends.
Percy could repress emotion in fanfiction through distraction. He may throw himself into his heroic deeds and adventures so he doesn't have to confront his inner feelings. By constantly being on the move and taking on new challenges, he can push his emotions to the side. Also, he might use humor as a defense mechanism. Making jokes in tense situations to deflect from how he really feels, which is a form of emotional repression.
One consequence could be a breakdown. Eventually, all those repressed emotions will have to come out. It might be at a really inopportune time, like in the middle of a battle or important mission. Another consequence is that it could lead to misunderstandings with his friends. Since they don't know what he's really feeling, they might misinterpret his actions.
Some fanfictions might suggest that Percy's control over blood is a new power he discovers while on a special quest. He might find out that his powers are not just limited to water bodies but can also extend to the fluids within living beings. He could start to experiment with this new - found ability, and at first, it might be a bit clumsy. But as he gets more practice, he could use it for various things, like healing (by manipulating the blood's flow to injured areas) or even in combat (by making an opponent's blood act in a way that disables them, like making it rush to their head and cause dizziness).
He could be angry. Percy might lash out at those who betrayed him, feeling a deep sense of injustice. He would probably be determined to prove his innocence and get revenge on those who wronged him.
In some fanfictions, Hermes interacts with Percy as a mentor. He might offer advice on how to deal with other gods or mythical creatures. For example, he could tell Percy the weaknesses of a particular monster. In other stories, he may be more of an enigma, his actions and words being hard to decipher. Sometimes, Hermes and Percy form an alliance, like when they have to face a common threat together.
He could also become withdrawn and depressed. Percy and Annabeth have a very strong bond, and her death would leave a huge void in his life. He might isolate himself from his friends and family, lost in his grief and memories of her.
In some fanfictions, Annabeth might calm Percy by simply talking to him in a soothing voice. She could remind him of their shared adventures and how they've overcome difficulties together.
Percy could also become corrupted in fanfiction if he experiences great loss or betrayal. If he loses someone very close to him and blames the wrong people, he might seek revenge in a way that corrupts his moral compass. He could start using underhanded or unethical means to get what he wants, which is a form of corruption.
In fanfiction, charmspeak can make Percy more influential. He can use it to persuade his enemies to stand down or his friends to follow his lead more easily.
Percy could also use his strategic mind. He has been through many battles and knows how to plan defenses. He might scout the area around Artemis and set up traps or early warning systems to protect her from any approaching danger. This would involve using his knowledge of the terrain and his skills in combat to ensure her safety.
Percy could use magic in fanfiction by having an innate ability that he discovers over time. Maybe he has a connection to a magical source, like a hidden well of magic within himself. He then learns to control and direct this magic, using it for various purposes such as healing, protection, or even offensive attacks. He might start with small, accidental uses of magic, like making a small flame appear when he's angry, and then gradually learn to master it through training or guidance from other magical beings in the fanfic.