Fear was a energy source not yet utilized by human beings, they did not have that technology, nor would they for another hundred years, but that did not mean that such things in the Universe, did not already exist.
There were things that lived off of fear, anger and hatred, especially hatred, because the light inspired hatred.
They were everywhere, and getting closer because the veil that separated life and death was simply a veil, a clever illusion out of the graspe of man, that seemed very solid, but that its appearance was only an illusion to the mortals because it was actually quite flimsy. From a distance the color of the Veil, which was transparent, surrounded by the blackness of space made it appear rock solid, when it was actually quite flimsy.
People who practice Black Magic, Witchcraft, and Voodoo pierced the fabric, and because of the true nature of the veil, the impermanence of it, sometimes things from the other side slipped under, around, or even between the veil itself.