Coming from a mostly unknown background, it can be implied that Strade has a number of psychological issues and fascinations. He is charismatic, a trait which many find very compelling. It can be implied that this trait, that many killers like him share, is his main device in luring victims.
As for his tendencies, Strade is a by the book definition of a sexual sadist. This implying he finds sexual arousal in making others suffer, which can also be seen in a number of his endings.