From Aurora Publishing:

Male by day & female by night...whoever looks upon her true form will meet with certain death. Abel is a member of the Nephilim – a unique race of people whose gender changes from day to night. Known as “Deathbringers,” it is said that whoever glances upon their bewitching nocturnal beauty will inevitably die soon after. Unfortunately for the playboy/Imperial soldier Guy, such an occurrence earns him this beautiful angel of death, hellbent on taking his life. Will Guy’s expert playboy skills be enough to conquer the beautiful Nephilim? Or will Abel succeed in killing the man who saw her true form?