A really cool plot could be that the children of Arachne are being wrongly accused of a series of crimes in the demigod world. Percy, being the son of Arachne in this fanfiction, decides to prove their innocence. He has to go through various challenges, like facing false witnesses, dealing with prejudice from other demigods, and uncovering the real culprit who is trying to frame the Arachne descendants.
One plot idea could be that Percy has to face Arachne in a battle of wits rather than just a physical fight. Maybe Arachne weaves illusions within her webs that Percy has to break through to reach her. Another could be a scenario where Arachne tries to use Percy to get revenge on the gods by tricking him into stealing an important artifact from Olympus. A third idea is that Percy and Arachne form an unlikely alliance when a greater threat emerges that endangers both of their existences.
One idea could be Percy having to use his charm powers (from being Aphrodite's son) to charm a powerful, ancient monster into sparing a group of demigods. He might struggle with the morality of using such powers in this way.
A plot could involve Percy being sent on a mission to an ancient Egyptian underworld realm by Sobek. There, he meets various Egyptian deities and creatures. He has to use his skills as a demigod and his new powers from Sobek to navigate through the dangerous realm and return to the mortal world with important information for the safety of Camp Half - Blood.
Another plot could be Percy discovering a long - lost relative among the children of Hades. This relative has some sort of power or knowledge that could change Percy's understanding of his own identity and his place in the demigod world. It could lead to a journey of self - discovery for Percy as he navigates this new family connection within the dark and often misunderstood realm of Hades.
Another plot could involve Percy having to prove himself to the children of Athena. Since he's not a child of Athena, they might be skeptical of his abilities at first. But as they face challenges together, like deciphering ancient prophecies that are hidden in Athena - related temples, Percy shows his worth through his quick thinking and battle skills. This could lead to a great friendship and mutual respect among them.
One idea could be Percy exploring his new powers that come from being the son of a Titaness. He might discover abilities that are different from his normal demigod powers and have to learn to control them quickly. For example, he could have the power to manipulate time on a small scale, like slowing it down in a battle to gain an advantage.
One idea could be Percy having to team up with Leto's other children in a quest to retrieve a powerful artifact that was stolen from their mother. Another could be Percy discovering a hidden connection between his powers and Leto's domain, leading to a new level of his abilities.
One idea could be Percy discovering new powers related to being the son of Pontus. For example, he might be able to control underwater currents in ways he couldn't before. Another plot could involve him having to face a new type of sea monster that is specifically drawn to his Pontus heritage. He could also go on a quest to find an ancient artifact related to Pontus that has the power to either save or destroy the underwater world.
Well, perhaps in the fanfiction, Percy discovers some hidden powers that come from being the son of Atlas. He could struggle to control these powers at first, which causes some chaos in Camp Half - Blood. And then, there could be a prophecy that only he, as the son of Atlas, can fulfill. It might involve traveling to a place that was once under Atlas's domain and facing creatures that have been long forgotten but are now resurfacing due to some dark magic.
Another plot could involve Percy having to deal with a powerful sea monster that is not from Greek mythology but from some other ancient culture's sea lore. He has to use his skills and the help of his friends in a new and different way to defeat it.