The Neromancer is a being of pure light and darkness thought into existance by the darkness in man's hearts and the light in their souls. Because of this there is only two Neromancers in all existance.
which means everlasting light
Latin for "eternal light"
The first is Lux Aeterna or just Lux. He is a serious alien being without a face, he glows like the sun and has a voice like thunder. Though mistaken as God at times even he has mentioned that " I am but a spec to the one you speak of..."
which means eternal night
The second is Nox. He is the opposite of Lux, he is pure darkness. A being of false hood and pain. Nox often appears to the viewer as the embodiment of their greatest fear.