Cistina Phoraena

She's one of the four daughters of Archiereus Mreuva Phoraena, younger sister of Cerya and Sherri, and older sister of Olivya. Formerly a sybil of the Order of Philaha, she was driven from her home when Abuna Brantyn ousted her father, and after the death of her mother she joined her sister Cerya in the Valerian Liberation Front. She's encountered as early as Chapter 1, but doesn't take a role until Chapter 2 of the Chaotic Route; in the Lawful Route, a grislier fate prevents her from appearing.