A concept art piece illustrating a malevolent demon with lifelike, elaborate details, featuring chaotic brush strokes that echo the late 20th-century concept art style. The composition is dynamic and flowing, with a focus on high contrast, employing a predominantly dark and ominous color scheme to evoke a sense of movement and drama. The demon's sinewy form is both terrifying and mesmerizing, with sharp, elongated features and otherworldly eyes. Shadows and highlights clash to enhance the nightmarish atmosphere, capturing the viewer's gaze and pulling them into the otherworldly chaos.