Who could betray Percy and Nico in a 'Percy and Nico are betrayed' fanfiction?

It could be a jealous demigod. Maybe someone who is envious of Percy's popularity and Nico's unique powers. This person might see an opportunity to get rid of them and take their place in the demigod hierarchy.

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.

Perhaps a new character introduced in the fanfiction. A seemingly friendly newcomer who infiltrates their group, gains their trust, and then betrays them at a crucial moment. This character could be working for an enemy force, either from the Titans or some other ancient power that wants to see the downfall of Percy, Thalia and Nico.

A powerful magician or sorcerer in the fanfiction world might betray them. Such a character could have their own agenda and see Percy, Jason and Nico as obstacles. They could use magic to create illusions and false evidence to make it seem like the three have committed wrongdoings.

Well, they could be betrayed by someone they trusted deeply, like a fellow demigod. Maybe this person spreads false rumors about them, leading to their isolation within the demigod community. The three of them would then have to struggle to clear their names and find out who really set them up.

In many Percy, Nico, and Jason - related fanfictions, the idea of betrayal can vary greatly. It could be that in some stories Jason betrays Percy out of loyalty to a different group or a misunderstanding. For example, if there's a power struggle within a camp and Jason believes Percy's actions might endanger the whole camp, he might take actions that Percy perceives as betrayal. However, it could also be Nico who is betrayed by the other two if they accidentally expose his secrets that he's been keeping to protect himself and others.

In a fanfiction about their betrayal, it could be that they are betrayed by a new character who infiltrates their group. This new character might seem friendly at first but then turns on them to further their own secret agenda, perhaps related to an ancient prophecy. Percy, Nico and Thalia would then have to figure out how to stop this new threat while also clearing their names.

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.

One possible reason could be jealousy among other characters. Maybe there are those who envy Percy's powers and leadership, Jason's status as a hero, or Nico's unique abilities. Another reason might be a misunderstanding. For example, they could be wrongly accused of a crime they didn't commit, which leads to others turning against them.

Maybe a character from their past who has a hidden grudge. Say, someone they defeated in a previous battle who has now found a way to get revenge. This person could pretend to be their ally again and then stab them in the back when they least expect it.