Apollo could be the most interesting. Imagine Percy growing up with Apollo's gifts of music, poetry, and healing. He'd be this multi - talented demigod. He could use his music to charm monsters or his healing skills to save his friends in a more unique way than just using a sword. Plus, Apollo's flamboyant personality might rub off on Percy, making him a more colorful character.
In my opinion, Athena would be the most fascinating god to raise Percy. Percy is known for his courage and fighting skills, but if raised by Athena, his intelligence would be off the charts. He'd be able to outwit his enemies in ways that go beyond physical combat. He'd be a master strategist, and his adventures would likely be more cerebral, with him using his wits to solve problems rather than just brute force.
Poseidon is a likely candidate. Since he is Percy's father in the original series, it would make sense for him to take a more active role in raising Percy. He could teach Percy all about the ocean, its secrets, and how to use his water - related powers more effectively.
One idea could be that Percy is raised by Poseidon. He grows up with a deep understanding of the sea and its powers from an early age. This might lead to him having a more solitary childhood as he has to hide his connection to the god. Another plot could involve Percy being raised by Athena. He would then be extremely intelligent and strategic, perhaps getting into trouble at school for being too smart. A third idea is if he's raised by Apollo. He could have a natural talent for music and healing, and his adventures might revolve around using these gifts in a world that is both dangerous and full of mythical creatures.
His old friends from Camp Half - Blood like Annabeth could be his allies. She would support him through the transition of becoming a god. Grover too, as his long - time friend, would be there for him. Also, some of the minor gods who have always been on good terms with Percy, like Hestia, might offer their help and guidance as he steps into his new role as a god.
In the Percy Jackson universe, it could be Chaos. Chaos is often considered one of the most ancient and powerful entities. If Chaos were the eldest god in the fanfiction, it would bring a whole new level of power and mystery. Percy would be dealing with a being that is essentially the origin of everything, and its motives would be very difficult to understand.
It could be Ares. He is often portrayed as a violent and unpredictable god. Percy might banish him if he goes too far in causing wars and chaos among mortals. His banishment would have a huge impact on the battlefields of the mortal world.
Apollo might be the betrayed god. He could have been tricked by another god into betraying Percy. For example, Apollo might have been promised more power or a higher status among the gods if he turned against Percy. But then he realizes too late that he's been used and that he's actually betrayed someone who could have been an ally.
In Percy Jackson fanfiction, Zeus is often considered one of the most powerful gods. He is the king of the gods, controls the sky and lightning. His power is so great that it can shake the entire world when he's angry. Just think about the times in the original stories when he showed his might, and in fanfiction, that power is often amplified even more.
Well, it could be that Percy is raised by a specific god like Poseidon but in a more direct and involved way. Maybe the god teaches him all kinds of super - secret powers and knowledge that normal demigods don't get. For example, he might be taught how to control water in ways that are far beyond what he learned at Camp Half - Blood. This could lead to him having a whole new set of adventures, facing different kinds of monsters and challenges that are related to the god's domain.
His mother, Sally, would surely be one of his allies. She has always been there for him. Also, Grover could be his ally as they have a long - standing friendship. Grover might see Percy as an even greater protector of the nature spirits now that he's a god.
I'm not sure which specific 'Percy God of Sex' fanfic you're referring to. There could be many interpretations of a character named Percy in different fan - created stories. It might be an original character created by the fanfic writer with their own unique backstory and characteristics within the context of that particular fanfic.