Falco: the Dark Angel

Detroit, once the richest city in the world, the crown jewel of America, home of architectural wonders, has fallen into deep decay, becoming a modern wasteland. Vast portions of the city are abandoned, filled with the detritus of a once great civilization. People still live in the city but have to deal with violent criminals who prey on the innocent while civic officials pretend they're in charge, forcing the police into a losing battle against darkness. Among the crimes the police are dealing with is a killer who beheads his victims, draining their blood. Trouble is, all these victims are scumbags.
This is where Falco walks. Falco the psychic, the finder of the kidnapped and tortured, who metes out retribution on evil men and women. While investigating one of the decapitation murders, a police lieutenant discovers Falco's possible involvement and launches an investigation into him. When he discovers what Falco is, he proposes a partnership that will solve crimes and provide Falco with a steady stream of worthy victims.
The arrangement works well until they discover a monstrous evil even greater than Falco demanding they unite to defeat it.