Angel
Angels are the bad guys. They are coming to Earth because conditions on their world have changed. They feed on the energy of humans leaving them weak, sick but enraptured. Alex hunts these angels. He is sent to kill Willow. She is something both humans and angels think is impossible--a half angel. When Alex finds out that the angels want her dead, he decides to help her. They are one the run and isolated. They need to stop the next wave of the angel invasion.