A piece of concept art showcasing a malevolent demon with realistic and intricate details, capturing its terrifying essence. The artwork features chaotic brush strokes reminiscent of late 20th-century concept art, with a dynamic and fluid composition. High contrast is employed to emphasize the dramatic interplay of shadows and light, with a color scheme that leans towards deep reds and stark blacks, evoking a sense of movement and tension. The demon, with twisted horns and fiery eyes, stands amidst a swirl of darkness, its muscular form surrounded by tendrils of smoke that suggest both power and malevolence.