A supreme grade forging material produced in the Demon Realm. It is pitch-black ore with a faint cold sheen. A fist-sized piece has a black market price of around 100 mid-grade spirit stones. Mixing it with swords can increase hardness by at least thirty percent. The protagonist had two high-purity pieces in her storage bag. One was sold for 500 mid-grade spirit stones to Zhao Youqian, and the other was reserved for upgrading the senior brothers' swords.
