Perhaps a plot where Percy is summoned by Khione to help her with a problem in her icy realm. There, he meets other children of Khione and they have to work together to stop a dark force that is melting the ice in her domain. Percy uses his skills as a demigod and his unique heritage to come up with a plan to save the day.
Well, one possible plot could be Percy discovering his new heritage as the son of Khione. He might struggle to come to terms with it at first. Maybe he has new powers related to ice and snow that he has to learn to control. He could also face challenges from the other demigods who are skeptical or even hostile towards this new revelation.
Well, a cool plot for a 'Percy Jackson Son of Khione Fanfic' might be that Percy is sent on a quest related to his new heritage. He has to find an ancient artifact that is tied to Khione's power. Along the way, he meets other demigods who also have unique powers related to cold or ice. They initially don't trust him because of his dual parentage but as they face challenges together, they learn to work as a team. He also has to deal with the internal struggle of being different from what everyone expected him to be.
Perhaps in the fanfiction, Percy discovers that his Romanov heritage gives him some unique powers or abilities. He then has to learn how to control and use these powers while also hiding his true nature from the outside world that might not understand or might try to take advantage of him.
Another plot could involve Percy discovering a hidden connection between Poseidon and Athena that was long forgotten. This could lead to a situation where he has to convince the other demigods that this connection is important for the future of the camp. Maybe there are ancient prophecies that only he can understand due to his unique parentage.
One interesting plot could be Percy finding a way to balance the powers of Chaos and Order within himself. He might have to face challenges where the two opposing forces are at war inside him, and he has to learn to control them without being consumed. For example, when he's in a battle, the chaotic side might want to go all - out destruction while the order side wants a more strategic approach.
A plot could involve Khione being banished from her icy realm for some reason. Percy takes it upon himself to help her. Along the way, they have to deal with various obstacles, including other mythological beings who are against Khione. Their relationship deepens as Percy stands up for her, and they share many tender moments as they figure out how to get Khione back home.
Well, one possible plot could be Percy struggling to adapt to his new 'mother' Khione. He might have to deal with her cold and often unfeeling nature. For example, she could be trying to train him in her own ways which are very different from what he's used to at Camp Half - Blood. Maybe she wants him to use his powers in a more aggressive way to serve her own purposes.
One interesting plot could be Percy having to face off against Medusa's other children in a battle of wits and strength. Maybe they are out to prove themselves as worthy as Percy, who has the fame of being Poseidon's son. Another could be Percy having to deal with the stigma of being 'Son of Medusa' in a world that fears her so much. He might have to constantly prove he's not a monster like his 'mother' is perceived.
In some fanfictions, there could be a plot where Percy is faced with a moral dilemma due to his connection to the 'Son of the Pit'. Maybe he has to decide between using a dark power within him to save his friends or resisting it and finding another way, which would show his growth and the struggle between his good nature and the darker aspects of his heritage.
One interesting plot could be Percy's struggle with his new identity as the son of death. He might have to deal with being feared by others in the demigod community. For example, he could face challenges when trying to form alliances as other demigods are superstitious about his parentage.