The Hyakki Gokai is a hyper-stylized, ornate weapon resembling a massive, curved blade with intricate engravings depicting mythical creatures and swirling patterns. The blade has a glossy, metallic finish with a vibrant, luminous edge that glows faintly, suggesting magical properties. Its handle is wrapped in dark leather, contrasting with the bright, polished metal, and features a large, ornate guard decorated with demonic faces and intricate carvings.