The Dissipating Man in Black

We finally tracked the source of the Void Mist to a mysterious person dressed in a pitch-black robe.
It was he who deliberately spread the Void Mist, causing all the strange Engram Anomalys on the plains.

When defeated, the Man in Black knelt on the ground, obsessively whispering, "How can such a grand cause be..." , and then dissipated into black mist.