As of now I have finished watching the Anime Campione and have realized that a crossover between that and Percy Jackson could totally work, this is only a minor crossover in which Perseus gains abilities from that show. If you haven't watched Campione, it is an anime in which humans can become God-slayers by killing a Heretic god. God-slayers gain some characteristics and abilities of any god they kill, the abilities are usually a watered down version that still has the power to overcome gods.
(1 Year Later)
A lot has changes since the death of Jay, Perseus had become more secluded and even less social, harboring a great grudge against the Olympian gods. His mother had never been the same, while she would never admit it she had blamed him for the death of Jay, never looking at Perseus the same since the day he returned to the cabin covered in blood. She had turned to alcohol in her grief and had married an awful man named Gabe.
However he had not been idle in the past year his grief has formed into an overwhelming hatred for any and all immortals in the Greek Parthenon. Perseus had channeled this hatred into mastering the use of his brother's dagger, he had also learned to manipulate water and was slowly improving. While in the beginning he could only lift the contents of a glass of water for one minute he could now hold an entire bathtub of water for ten minutes. Perseus had also discovered another ability, if he strained himself enough he could manipulate the molecules in water to form ice however he was still too young and weak to hold this for more than twenty seconds without obtaining a severe nose-bleed.
While it is abnormal for someone as young as eight to have such control over godly powers, Perseus had pushed his body to his limits discovering that as long as he stepped into a water source after training his body would repair itself within minutes. this led to him lifting extreme amounts of weights and running laps with rocks tied to his small legs, until his arms and legs where severely damaged before dragging himself to the bathtub he had previously filled and allowing himself to heal.
But that was not all he had a severe case of insomnia which he was able to hide by constantly having bottles of water at hand, whenever he was noticeably exhausted he would tip the bottle over his body allowing it to renew his stamina. At this point many would call him insane however he did not care for the opinion of others and only wished for his revenge. This continued until one summer night before his eighth birthday, a night which would change not only Perseus's destiny but that of the entire world.
Perseus was sitting at his desk within his room reading a book about water molecules, he had decided that if he could learn to control water within the air he would also be able to control the human body to a certain degree. He imagined a hunter of Artemis's scream as he forced her blood to explode out of her body bringing about her gruesome end while Artemis could only cry out in shock, struggling as a tentacles made of water held her against a wall, at his mercy and then…
Perseus's dark fantasy was brought to an end by a voice, "Hmmm I see a willful mortal with dark mind to match, ohhhh and that deep hatred for the Olympians, very impressive," spoke an enthusiastic, feminine voice carrying a sense of power.
Perseus jumped from his seat lunging for the dagger on the table behind him, he grabbed it before getting into a stance, ready for combat. "Who are you," he yelled into the air around him, seeing no sign of the being that had spoken. He heard a giggle behind him turning around he saw a peculiar sight. A girl around twelve years old but that was not the strangest part, her left side was black and hardened like a mummy while her right side was pale and chalky as if she were drained of all her blood. The girl was wearing a golden dress and shawl, with eyes like empty black voids. Perseus thought for a moment before speaking "You are Melinoe, The Greek goddess of ghosts."
"You are correct demigod, while I dislike your kind you seem to be an interesting specimen," she looked at him for a moment seemingly staring into his very being, before speaking again. "You see we both currently have a problem with the Olympian council, I wish to haunt the mortals of the living world, have them remember the terror they faced in the golden age of Greece," Her eyes brightened as she said this her face gaining a truly terrifying look. "However my father….. Hades," she spat the name like just the thought of it left a bad taste in her mouth. "Refuses to allow me free rule, saying that he has enough on his plate without me scaring 'innocent' mortals into insanity.' she finished, her face still holding a truly cringe worthy look of pure evil. "I will assist you in gaining your revenge… but only if you help slay my father."
Perseus who up until this point had been listening carefully, still on guard for any attack that would come his way finally spoke "and how can I help you with this."
The goddess giggles looking to all the world like that was the exact question she wanted asked, "Well gods cannot act directly because of the ancient laws, we can have someone. A mortal act in our steed" 'and who better than a child of the big three with a direct link to the great prophecy' she thought looking at him hungrily.
Perseus was quiet for a moment before speaking "and what does me a mere mortal have to gain from this?" he spoke in a detached but clearly interested tone.
"After centuries of searching the minor gods have found ancient texts detailing what a Campione is and how they come to be, they are mortals who have somehow killed a God without assistance, Gaining abilities similar to those which the god had. Perseus finally gained an understanding of his role in this game. "And how would I a mere 'mortal' kill a god on my own." he said uttering the world 'Mortal' like it was a disease.
Melinoe wasted no time at all replying "We have found a minor god who wishes for his existence to end, however he doesn't wish to fade to the void while the rest of us are ruled by tyranny. You will kill Pan and gain true power." She sighted wickedly
Perseus stopped to think for a moment, if he accepted this offer he could shed his mortal skin and have the power to obtain justice, on his brother's behalf. "I accept, when can the process begin?"
Melinoe almost let out an evil laugh, she knew that Perseus would never reject such an offer, he had spent much time and effort attempting to gain power but it was never enough for him, now not only was he receiving power free of charge but also gaining an ally with similar goals to his own. Instead still acting the image of a child she let out a giggle "I can take you to him right now if you are sure."
All he could do was nod before Melinoe let out a high pitched giggle and the world around him began to fade.