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 fanfiction where they go to high school, Percy would likely be popular for his heroic deeds and good looks. He might join the swim team and break all the records. Thalia could be the cool girl who rides a motorcycle to school and gets into trouble for parking it in the wrong place. Nico would be the mysterious new kid. There could be a plot where they have to team up to stop a monster that is lurking in the school basement.
Perhaps it's a fanfiction focused on their relationships. They might form an unexpected bond in the story. Nico, who has often been a bit of an outcast, could find real friendship and acceptance from Percy and Thalia. They could start out on a simple quest, like finding a lost artifact, and during this journey, they learn more about each other and grow closer as friends.
Well, their relationships might become more complex. For example, Percy and Thalia might have a different dynamic as they see each other in a new light in the past. Since they are in a different time, they may rely on each other more for survival, which could strengthen their bond. Nico, being a bit of an outsider among them, might find himself more in tune with Percy and Thalia as they face the challenges of the past together. They may also form new relationships with people from the past, which could in turn affect their relationships with each other.
Well, one possibility could be that they are given special status on Olympus. Maybe they are tasked with keeping the peace among the gods, which would lead to a lot of interesting interactions with the deities. They might also use their unique powers to improve the living conditions on Olympus, like Percy controlling water to create beautiful fountains or something.
It could be that they run away to find someone. Maybe a missing demigod friend or a powerful being who can help them with a problem they're facing. Percy, Thalia, and Nico might have received a mysterious message or a vision that leads them on this journey. As they run away and start their search, they encounter various obstacles. They have to cross dangerous terrains, deal with unfriendly gods or demigods who don't want them to succeed, and also figure out how to work together effectively. Their friendship is tested, but in the end, they grow stronger together.
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.
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.
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 could be like siblings. Percy and Thalia might act as the older siblings, protecting and guiding Nico. Percy, with his leadership skills, and Thalia, with her combat abilities, would be great at looking out for the younger Nico. They could also be like cousins, with a close - knit bond but still having their own individual family heritages that sometimes create interesting dynamics.
One challenge is the jealousy of other gods. Since they are new gods, the older, more established gods might not like the attention they get or the new ideas they bring. Another challenge is controlling their powers. As mentioned before, going from demigod to god means a huge jump in power level, and it's not easy to get used to. For example, Percy might accidentally flood a city while trying to create a small puddle for fun.