Final Fantasy XIII, a role-playing game released by Square Enix in 2009, revolves around the struggles of a group of humans over a predestined fate. The game's two sequels, Final Fantasy XIII-2 and Lightning Returns: Final Fantasy XIII, build on the first game's story and mythos. In video game publications and among the staff at Square Enix, the three games have come to be referred to as the "Lightning Saga", and the core concepts they contain are drawn from the mythos of the Fabula Nova Crystallis subseries. The visuals of the original characters were designed by Tetsuya Nomura and Nao Ikeda, while many later characters were created by other designers, including Hideo Minaba, Yusuke Naora and Toshiyuki Itahana. Their original stories were created by Motomu Toriyama and written up by Daisuke Watanabe. The series' central characters are Lightning, a former soldier and the core character in all three games; Serah Farron, Lightning's sister and the second game's main protagonist; Snow Vil...