The poster for Mandy has basically zilch to do with Bill Duke – his face is blended in that ectoplasmic cast sketch in its background – but it should, I think. He’s critical to the film’s bizarre-o world gelling together, a normal (“normal”) character in what amounts to an 80s metal themed D&D campaign where Nic Cage crafts a battle ax and does coke plus other Mystery Substances™ (because what else are you supposed to do with the unknown contents of a jar sitting on the kitchen countertop in a house inhabited by horny demons?), and yeah, well, you get the idea.
Without Duke, I’m not sure the movie transitions as well from surreal horror of the senses to surreal horror of the senses plus revenge plus batshit lunacy. So I paid him homage in a piece for The Hollywood Reporter.