By this point, Bruce Wayne is constantly seen wearing turtlenecks, signifying yet another of many homages/tributes to the Tim Burton Batman films.
The Shaman mentions "Seek out the Demon's Head..." this is a reference to Ra's Al Ghul in DC Comics.
The title "Pretty Hate Machine" is the title of the album released by Nine Inch Nails on October 20, 1989
Bruce wears black turtlenecks symbolizing Batman. In this episode, however, he wears an off-white textured turtleneck that visually resembles the breast of an owl, symbolic of his brainwashing by the Court of Owls.
The Shaman's words to Bruce Wayne echo those of Zeus (Laurence Olivier) to Perseus (Harry Hamlin) in "Clash of the Titans " (1981): "Find, and fulfill your destiny!"