Sylvia's younger sister, Irene, disappeared long ago after being driven away by the gods' maltreatment of her. When Irene suddenly appeared at the Sky Castle, Sylvia and her knights made haste to its location. Sylvia's heart tightened from the guilt she felt in being unable to protect her sister. "If I can apologize to her, perhaps we can live together in peace as we once did." However, when she saw the evil creatures swarming around the castle, she realized her desire may never come to be.