Well, perhaps Percy and Nico could be transferred to Hogwarts through some sort of magical accident. Maybe they'd have to deal with the different magical system there compared to their own world. They could make new friends among the Hogwarts students and get involved in the typical Hogwarts adventures like the Triwizard Tournament or dealing with a new dark threat.
In this fanfiction, they might start by being really confused in Hogwarts. Percy, with his leadership skills, could try to figure out how things work. Nico, being more of a loner, might initially struggle with the social aspects. Their powers from their original world could interact in strange ways with Hogwarts magic. For example, Nico's ability to control the dead might be seen as a very dark and strange magic in Hogwarts. And Percy's water - controlling powers could be a new and interesting addition to the Hogwarts magical scene. They could end up teaming up with some of the well - known Hogwarts characters like Harry, Hermione and Ron to face a common enemy.
Well, one possible plot could be Percy and Nico having to deal with typical high school problems like bullies. Percy might use his water powers in a discreet way to stop them. Nico could be the mysterious loner at first but then make some real friends as he shows his cool powers. And they might also have to hide their demigod identities from the normal students.
They would surely meet Harry Potter. Harry could be curious about their different magical abilities and background. Hermione would also be there, probably peppering them with questions about their own world's magic. Ron might be a bit skeptical at first but warm up to them eventually.
In this kind of fanfiction, they might face challenges adjusting to the new magical environment. Percy could be confused by the different types of magic in Hogwarts compared to his own demigod powers. Nico might struggle with the more structured and rule - bound nature of Hogwarts. Thalia could find it interesting but also be a bit rebellious against some of the Hogwarts traditions.
Percy would probably be very friendly and try to form study groups with the Hogwarts students. He's used to being a leader, so he might even start some new clubs. Thalia would be a bit more standoffish at first, but once she gets to know some students, she'd be very protective of them. Nico would be the mysterious one. The Hogwarts students might be a bit scared of him at first, but once they see his softer side, they'd become friends.
Well, perhaps they could be exchange students. Percy might use his strategic skills from Camp Half - Blood in Hogwarts' challenges. Hazel could show off her knowledge of ancient magic which might be similar in both worlds. Piper might use her charm - speaking to deal with the Hogwarts students and even some magical creatures. They could also form an unlikely friendship with the Hogwarts students and get involved in the fight against the Dark Arts.
They could have all sorts of adventures. Maybe they'd get sorted into different houses and have to deal with the rivalries that come with that. Percy might use his water - controlling abilities in the Hogwarts' lake, and Thalia could use her lightning powers during a stormy Quidditch match. Nico could explore the Hogwarts' underground secrets, using his underworld - related skills to uncover hidden chambers.
The main plot could revolve around fixing a mistake in the past that has led to a distortion in the present. For instance, something might have happened in the past that changed the balance between the different camps of demigods. Percy, Thalia and Nico go back to set things right. They'd encounter different cultural and technological aspects of the past time period. And they would likely face opposition from those in the past who don't understand their motives or are being influenced by the very thing they are trying to correct.
In a 'Percy and Nico are betrayed' fanfiction, perhaps they are betrayed by the gods. The gods, fearing their growing power, might spread lies about them among the demigods. Percy and Nico then have to fight not only against the false accusations but also the demigods who turn on them. They would have to find a way to clear their names and prove their loyalty.
Well, it could be that Percy yells at Nico because he feels Nico is being too reckless in a dangerous mission. Maybe Nico is about to do something that could endanger the whole group, and Percy, being the protective type, loses his temper.
In this fanfiction, perhaps Percy adopts Nico after Nico has been ostracized by the other demigods. Percy realizes that Nico needs a safe space. So he offers his home. As time passes, they start to understand each other better. Nico might open up about his past traumas to Percy, and Percy would use his own experiences to help Nico heal and feel like he belongs.