The Blackened Temple Key is a medium-sized, intricately designed key with a dark, ominous appearance. Its shaft is made of a blackened metal, possibly iron or obsidian, with a rough, weathered texture suggesting age and frequent use. The bow of the key features an ornate, symmetrical design resembling a demonic face or ancient sigil, deeply engraved and slightly glowing with a faint, eerie red hue, hinting at its magical properties. The teeth of the key are complex and angular, designed to fit a specific, ancient lock within the temple's depths.