A Demon Core is an energy crystal capable of increasing skill levels and item quality.
Holding the black crystal in his hand, Yan Ao felt a surge of information appear in his mind.
According to Xie Renjie, this item functioned just like Sublimation Crystals, Blood Soul Stones, and other such items. Under normal circumstances, they only had a certain chance of dropping when one killed special monsters that appeared during a Death Game under the intervention of a Death Option.
Chapter 348