Title: Percy, Nico and Thalia Betrayed - Fanfiction Analysis

Another idea for a fanfiction where they are betrayed is that they are betrayed by a trusted mentor figure. This mentor could be influenced by dark forces or simply have a change of heart. As a result, Percy, Nico and Thalia are left to face challenges alone that they were previously relying on the mentor for support with. They would have to grow and become stronger independently to overcome these difficulties.

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.