"The darkness can be both a great ally and the fierce enemy to us, foolish mortals. It is a veil most welcoming, an illusion most treacherous, a weapon most potent. Then, would you really be surprised to hear of the people who learned to tap into this archaic existence and repurpose it into a weapon? Umbramansy they call it.
An Umbramanser taps into the black mass and bends it to their will, using the neural patterns of their mind to shift it into weapons, tendrils, walls, etcetera. Many band together, forming schools with their own sets of doctrines, philosophies and modus operandi, while others - "Independent Umbramansers" prefer a more solitary form of life. Their styles are one of a kind, unpredictable and dangerous. In pursuit of this power, many willingly strip themselves of their memories, humanity, identity, and even sexual characteristics, transforming into pale monstrosities, that pursue the call of power above all else." - An unnamed hermit.