Angel (1999 TV series)
The series tells the story of the vampire Angel. Angel had his soul returned to him as punishment for killing a gypsy girl. This made him tormented by all the bad things he had done.  During the first four seasons of the show, he works as a private detective in a fiction version of Los Angeles, California. There, he and a variety of others work to "help the helpless" and "save the souls" of those who had lost their way.  This usually meant fighting evil demons or humans that worked with demons (the law firm Wolfram and Hart). He also had to fight his own violent nature. (Not all "demons" in the Angel universe are evil beings.) The fifth season saw Angel taking over as the person in charge of the evil law firm Wolfram and Hart. This was done to try to fight evil from the inside.