The Hyakki Gokou is a hyper-stylized, ornate mask inspired by Japanese folklore, featuring exaggerated demonic features with sharp, angular lines and glowing red eyes that emit a faint luminescence. The mask's surface is a mix of polished black lacquer with intricate gold engravings depicting mythical creatures, giving it a battle-ready yet ceremonial appearance. Its design includes protruding horns with a slight curve, adding to its menacing aura, and the edges are lined with a crimson fabric that flutters dynamically during movement.