The Soul Chamber Key is a mystical artifact with an ornate, gothic design, featuring intricate engravings of ancient runes and symbols that glow with a faint, eerie blue light. The key is crafted from a dark, metallic material with a slightly weathered texture, suggesting age and frequent use. Its handle is shaped like a demonic skull, with the key's teeth forming a complex, asymmetrical pattern that seems to pulse with energy when held.