One way of getting here, The Concave, is through conflagration of your Soul. Not a nice way to arrive, but at least you'll have the benefit of a guide, unlike most others.
Serpens Necto is a mask made of snake skins stitched together and crudely painted in white. With this on a person can bind people to their will under the right conditions. In darkness the effect of the mask is greatly enchanced by illumination from under by a candle.