How bad is it? Might be Andy Milligan's best horror film, which means awful. Just awful.
Should you see it? If you feel you must find out what Andy Milligan films are like.
Shortly after breaking my vow not to review Milligan films, here's the second one. It's extremely cheap, with sets made by draping sheets and "medieval" costumes that are laughable. A monk maintains an island church (St. Peter's in NYC - how did he swing that?!), where criminals are punished and executed. He also robs graves. He has a one-eyed hunchback assistant named Igor. He has a witch/vampire mistress. There's better acting than usual, with the lead character being passable. The film is very talky, as usual, with monotonous exposition delivered in monotone. There's some terrible effects; obvious mannequin limbs are chopped off. The score, though competent and fitting the scene (vaguely religious) adds to the general dull drone of the film. Fortunately, with a run time of about an hour, it only hurts for a little while.