Castile is a young wheelchair-bound girl, whose family was rich before spending most of their fortune on her treatments. She is kidnapped by minions of Sulphur, but rescued by Marona and Ash. Castile learns about Marona's ability to see phantoms, and meets with Ash, and she and Marona become best friends as the events of the story unfold. According to an after-game bonus map in the PS2 game "", Castile eventually recovers from the sickness that keeps her in bed and becomes healthy enough to fight alongside Marona, while searching for signs that her brother Walnut may still be alive.