Godspeed on the Devil's Thunder is conceptual and is based on the well-documented, true-life fall from grace of a shadowy historical figure named Gilles de Rais, a wealthy French nobleman who was one of Joan of Arc's brothers-in-arms. He was best known, however, as a prolific serial killer who mixed prayers with his nightly murders as well as an aspiring alchemist. He was accused of a panoply of crimes, among them heresy, demonology and kidnapping. There's even an extreme fringe sect of historians who question de Rais' true status, with some convinced he was framed.
Title track downloadable here.