Well, it depends on the writer's take. Maybe Rhea sees something special in Percy, like his heroism. Thalia's fierce nature might impress Rhea as well. Nico's connection to the underworld could be of great interest to Rhea. They could form an alliance. For example, Rhea could guide them to a hidden place full of powerful artifacts that they need to defeat a new rising evil in the world of the fanfiction.
In fanfiction, they might have an epic adventure. Percy could use his water powers to protect them if they encounter any danger. Thalia with her lightning might strike down foes. Nico could summon the dead to get information. Rhea might offer them some ancient wisdom or a special quest to save the world.
Well, they might lose trust in their friends. For example, if they were betrayed by someone they considered a close ally in the demigod world, like a fellow camper at Camp Half - Blood. Percy could become more withdrawn, as he has always been a bit of a loner at heart. Thalia might turn bitter and angry, using her skills as a hunter more aggressively. Nico, being the son of Hades, could potentially be pushed towards using his darker powers in retaliation, perhaps even seeking vengeance in the Underworld's way.
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.
In the fanfiction, they could be given important missions. Maybe they are tasked with restoring balance in a part of the Chaos realm that has been thrown into disorder. Percy's leadership skills, Thalia's combat experience, and Nico's knowledge of the underworld could all be put to good use. They would have to work together, which might not be easy at first given their different personalities. But as they face challenges, they would grow closer and become a more effective team.
They could be sent on epic quests by Chaos. Maybe they have to retrieve some powerful artifacts that were lost in the chaos of creation. Along the way, they would face numerous challenges and meet all kinds of strange creatures. Percy would use his strategic thinking, Nico his knowledge of the underworld, and Thalia her leadership skills to overcome obstacles and make their way towards their goal.
It could be a mentor - mentee relationship. Rhea, with her vast knowledge, could mentor the three. Percy might look up to her for guidance on his powers. Thalia could learn about her family's history from Rhea. Nico could gain insights on the gods' relationships from her.
Perhaps it starts as a misunderstanding. Percy might misinterpret something Nico does as a threat to his friends. Thalia, being Percy's friend, jumps in to defend him. Nico, feeling attacked unjustly, then retaliates. It could turn into a full - on fight with them using their powers. Percy with his water - based powers, Thalia with her lightning, and Nico with his control over the dead. The fight could be a very intense and action - packed scene in the fanfic.
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, it would be quite chaotic. Percy could teach a water - based magic class, perhaps something related to controlling water elements. Thalia, with her electric powers, might teach a class on lightning - like spells. Nico, being the son of Hades, could teach about the darker aspects of magic, like dealing with the undead. But they would also have to adapt to Hogwarts' rules and traditions which would be a hilarious and challenging process.
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.
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.