A nightmarish portrayal of an evil Japanese Oni, inspired by the rich cultural folklore, depicted in a dramatically detailed, hyperrealistic 8k splash art style. This mid-shot portrait captures the essence of a terrifying presence with an intricately detailed face, portrayed at a 2/3 angle to enhance the menacing aura. Bathed in side light, the Oni's features are starkly contrasted against a vibrant, colorful background that intensifies its horrifying visage. The depiction includes deliberate imperfections with a twisted, disfigured appearance, including mismatched eyes and a crooked grin, creating an unsettling visual experience. The composition plays with the boundaries of realism, presenting slight exaggerations in anatomy and expression, amplifying the surreal and nightmarish essence of the subject.