Luna is a mysterious girl who appears in the anime Casshern Sins. She is known as the Sun that was Named Moon and is regarded as the Source of Life for the robotic world. She possesses the fantastic power to heal and grant life, making her the focal point of hope and despair in a decaying world. Her very existence is tied to Casshern, as her death at his hands triggers the Ruin, a catastrophic event that causes robots to rust and die and the planet to deteriorate. She was summoned by the people to bring salvation, but Braiking Boss, fearing her influence, ordered his strongest cyborgs to eliminate her. Casshern succeeded, but the act set the world on a path to destruction. In terms of personality, Luna is initially portrayed as a warm-hearted and optimistic being. She believes that by granting death she can free those suffering from eternal life. However, after being killed, her perspective shifts; she becomes afraid of death and instead begins granting immortality to those she deems worthy, refusing to heal those she considers too far gone into suffering. She loves and respects Dune, viewing him as her guardian angel. Her role in the story is that of a hidden antagonist and the catalyst for the entire conflict. She is the embodiment of salvation and the tragic price of escaping death. Her key relationships include Casshern, whose murder of her defines his quest for redemption, and Dune, who serves as her protector. Throughout the series, Luna's character development moves from a benevolent figure seeking to save humanity to a more complex figure who selectively bestows immortality, reflecting her own trauma and disillusionment. Her notable abilities include healing, granting life, and the power to bestow eternal life upon others.