Black Crystal is exceptionally sturdy; it belongs to a higher tier than Mourning Purple Gold among the Undead entities. Yet, Black Crystals divide into Chaos Black Crystals and regular Black Crystals. If Chaos Black Crystals are alive, then regular Black Crystals are dead, merely a very hard material.
Back then, on the body of the Void War Tree, a huge Black Crystal was mined, but at that time, Ange had no way to use the Black Crystal, and it was useless in his hands.
However, now things are different. By using a sputtering coating method, Ange can coat many items with a layer of Black Crystal on the surface, instantly granting them exceptional hardness typical of regular Black Crystals, vastly enhancing their defensive power. According to the Monarch, having Black Crystal coating might even become a key for the Lord of Mourning to break through Chaos Black Crystal.
