The Hyakki Gokoku is a hyper-stylized, ornate katana with a blade that gleams with a supernatural luminescence, reflecting its mystical origins. The hilt is wrapped in dark, weathered leather, contrasting with the polished, mirror-like finish of the blade, which features intricate engravings of mythical creatures. The guard is asymmetrical, designed with sharp, angular motifs that resemble demonic faces, adding to its menacing aura.