Returning from a quest, Percy, Annabeth, Nico, and Will encounter a monster when it is suddenly killed by a single, specific blade which was thrown from the trees behind them. It had been her —daughter of Hades, Nico's big sister, and Bianca di Angelo's twin sister and maybe the most powerful demigod alive — Nico had never told the others about her, but she and Nico had a good relationship. She was confident, solitary and intense. She was identical to Bianca except she had long curly black hair. Her weapon was a blade (like the material used for her brother Nico's sword). she has always been Bianca and Nico's opposite in character. She was very sexy with a strong character, provocative, calculating, who hides behind a biting irony a deep loyalty, confident, intelligent, and very good at fighting. She is outgoing, with a strong personality and humor. She had taken a sabbatical because of a promise she made to her twin: She would have to take a break from everything until she had unlocked all her powers to be able to better protect Nico (only she and Bianca knew the details of the promise, Nico only knew that she and Bianca had made a promise).