Show their differences first. Nico is more of the brooding, dark - type while Percy is the optimistic hero. Have them clash over their approaches to problems. But then, when they are in a really tough situation, like being trapped in a maze created by a powerful enemy, they realize that their different perspectives are actually useful. Nico's knowledge of the Underworld and Percy's skills in the water and combat complement each other. They start to communicate better and develop a bond based on mutual respect.
You can start by having them share a common goal. For example, they both need to retrieve a powerful artifact that has been stolen and is being used for evil. As they search for it, they face obstacles that force them to rely on each other. This builds trust gradually.
Another way is to give them a personal reason to care about each other. Maybe Nico discovers that Percy has a connection to his past that he didn't know about. Or Percy finds out that Nico has been secretly protecting him all along. This newfound knowledge makes them see each other in a different light and they start to build a deeper relationship as they explore this new aspect of their connection.
In some fanfictions, their relationship might develop because of a common enemy. The threat of this enemy forces them to put aside any differences and work together closely. As they do this, they start to see the good in each other. Nico might see Percy's leadership skills, and Percy might see Nico's hidden strength and loyalty. They gradually become closer friends or even something more, depending on the nature of the fanfiction.
At first, it might be rocky. Percy is more of a laid - back hero, Nico is the quiet and often misunderstood one, and Jason is the dutiful leader type. But as they spend more time together, they start to see the good in each other. Percy might teach them how to have fun and not take everything so seriously. Nico could show them the power of the underworld and its secrets. And Jason would bring a sense of discipline and strategy to their group.
One idea could be that Nico and Percy are forced to team up on a quest that involves both the Underworld and the Sea. They start off distrusting each other because of their different powers and backgrounds, but as they face challenges together, they begin to understand and respect one another.
They could have a fight and then make up. It's a classic way to develop a relationship. Maybe Nico does something Percy doesn't like in the name of protecting him, and they argue. But then they realize they were both just trying to look out for each other and become closer.
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.
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.
The camp leaders might betray them. If there is a power struggle within the camp, and Percy and Nico are seen as threats to the current leadership's power, the leaders could set them up. They could make it look like Percy and Nico are breaking camp rules or endangering the other campers, which would lead to the rest of the camp turning against them.
Fanfiction involving Percy, Jason, and Nico can be really interesting. It often explores different relationships and adventures among them. For example, it might focus on their teamwork during a new quest in the world of Greek mythology. Writers might play with their different personalities - Percy's laid - back heroism, Jason's more disciplined leadership, and Nico's brooding yet powerful nature - to create unique storylines.
Well, they might use their combat skills. Percy, with his control over water, could create barriers or use water attacks against threats. Thalia, with her lightning powers, can strike down enemies. They could also use their strategic thinking, like leading Nico to safe places and standing guard over him while he rests or recovers his strength.
Their relationship could develop slowly. At first, they might just be acquaintances who respect each other's abilities. Then, as they spend more time together, they start to have small conversations that gradually become deeper. Eventually, they realize they have feelings for each other.