The mainstream entertainment world doesn’t get a lot of animated dark fantasy. So, besides outliers like Fire & Ice, Heavy Metal, and, to a degree, Netflix’s Castlevania, if you wanted to dive deep into mystical and alluring universes in the world of adult animation, your choices are finite. Now enter a curious entry called The Spine of Night. It clicks most of the boxes those titles occupy, and then some. Sorcery? Check. Wildly imaginative? Check. Violence, nudity and dazzling visuals? Check, check and check! The Spine of Night is an epic fantasy tale about the history of a land that never was. The story begins when an ambitious young man…