The Otherworld is the inversion of the world known as Valoris, formed primarily by the Boundary Stones of the Fair Folk. This mirror of the physical world only exists in certain places, thanks to the continuing advancement of human civilization. The rebuilding of the nature to humanity's whims is slowly encroaching on Fair Folk's collective light and causing irreparable harm to the world contained within.
A Boundary Stone, referred to by well-versed occultists as a Terminus, is the light of the soul, a sacred place where no one may intrude. The collective power of the Fair Folk's light is