Who is Luna from For Love of Evil and what is their importance?

Luna is the black magician's daughter. She loves her father above all others and respects him. When her father died, Luna was charged with the burden of carrying half of his sin, thus she carries not only her own sin but her father's as well. In the end, Luna sacrifices her life for that of another, balancing her sin and making herself worthy of purgatory instead of hell.