Perhaps Percy's niece is suddenly transported to a different realm in the world of Greek mythology. This realm is in chaos due to some dark magic. She has to use her wits and any latent abilities she has to survive and find a way back. Meanwhile, Percy is on a quest of his own but starts to notice strange things that lead him to suspect his niece is in trouble. Eventually, their paths cross and they team up to save the day in this strange new realm.
The niece could be a descendant of a minor Greek god that has been forgotten. She starts having strange dreams about this god and decides to investigate. In her journey, she uncovers secrets that could change the balance in the world of demigods. Percy, being her uncle, gets involved when he realizes the potential danger. They have to face many challenges together, including some enemies who want to keep these secrets buried.
A rogue magician who has a vendetta against Percy's family. He sees Percy's niece as an easy target to get back at Percy. He uses his magic to manipulate the world around her, causing confusion and danger. He might also be trying to steal her powers for himself to gain more influence in the world of magic and mythology.
One idea could be that Percy's niece discovers she has a unique power that no one else in the family has. Maybe she can communicate with sea creatures in a different way than Percy. Another could be that she gets involved in a quest that was thought to be only for the main heroes in the Percy Jackson world, and she has to prove herself to the other demigods.
Another character that could be included is Clarisse. Her tough - as - nails attitude could contrast with the niece's, and they could start off as rivals but eventually become friends. Also, Tyson, Percy's cyclops half - brother. He could be like a big, protective figure for the niece, and his unique abilities could come in handy during adventures or when the niece is in danger.
One idea could be that the adopted children have special powers related to different elements, like one can control water in a unique way different from Percy. They could go on a quest to find a lost artifact that is key to their new family's safety.
A cool plot could be that there is a prophecy in both the Naruto and Percy Jackson worlds. It predicts the coming together of a shinobi and a demigod to save both realms from a powerful, interdimensional evil. Percy arrives in the Naruto world, and he and Naruto have to learn each other's skills. Percy teaches Naruto about Greek mythology and how to fight mythical creatures, while Naruto shows Percy the ways of chakra and ninjutsu. They then journey to different parts of the Naruto world, gathering allies and knowledge to face the impending doom.
Well, perhaps she's on a quest. The Avengers mistake her for a threat at first. She's looking for a magical artifact that has the potential to either save or destroy both the demigod and superhero worlds. Along the way, she teams up with some of the younger Avengers like Spider - Man or Shuri. They don't trust each other fully at the start, but as they face various challenges together, they start to respect and rely on one another. And she's constantly in touch with her demigod family, getting advice from them about how to handle the superhero situation.
One possible plot could be that the Volturi from Twilight discover the existence of demigods from the Percy Jackson world. They see the demigods as a threat to their vampire supremacy. Percy and his friends have to team up with some of the more friendly vampires, like the Cullens, to fend off the Volturi. This would bring together the magic and powers of both universes in an epic battle.
Well, perhaps there's a villain in the Percy Jackson universe who discovers that the iCarly web show has a huge following and decides to use it as a way to spread chaos. The demigods have to team up with the iCarly crew to stop this. The iCarly gang has to learn about the world of Greek mythology really fast and help the demigods navigate the modern world of technology and media to defeat the villain.
Well, it could start with a magical accident. In the Percy Jackson universe, a spell gone wrong sends Percy, Annabeth, and Grover into the land of Alagaësia from Eragon. There, they discover that the demigod powers Percy has are seen as a strange and new form of magic. Eragon is initially suspicious of them but realizes they can help in his fight against Galbatorix. They combine their skills, Percy's water - controlling powers and sword - fighting skills, along with Annabeth's strategic mind and Grover's nature - sensing abilities, with Eragon's dragon - riding and magic - wielding skills to take on the dark forces.
The plot could involve a powerful magical artifact that has military applications. The NCIS comes across this artifact during an investigation but doesn't understand its true nature. Percy Jackson and his friends, who are on a quest to retrieve the artifact for the demigod world, cross paths with the NCIS. There is a lot of miscommunication at first as the two groups have different goals and ways of operating. But as they realize that they are both facing a common threat from a group of rogue demigods and power - hungry military personnel, they join forces. Percy uses his knowledge of the demigod world and his powers to help the NCIS agents navigate the magical aspects while the agents use their resources and combat training to take on the human threats.