Despite the (English) title, this seems to have little to do with Devils and much more to do with a power hungry ruler who seeks the Philospher's Stone & wants gold made from lead (& virgin's blood). Jacinto Molina plays Gilles de Lancre and seems to have little issue with having people put to death when he thinks they threaten his position or when he needs virgins for their blood. He's basically egged on by his lady love and an alchemist that he's employed and it's more greed and insanity that seems to be his problem than demonic possession (unfortunately). There are parts that are at least somewhat exciting like jousting and grown men trying to knock each other down with big sticks, and the film at least has a good look to it, but otherwise there's little about this to recommend. Little in the way of gore and nothing to be afraid of at all, and most unusual, for a Molina/Naschy film, not really any unintentional humor. Therefore, 4 out of 10.