Denizens, Facet 'Demon' is a colloquial term used for the hybrid humanoid being that is created when a Human and a Spirit create a pact to bind their souls together. The resulting process is known as Demonic Transformation and results in a physical fusion of both parties, creating a magically empowered humanoid creature who largely resembles the human part of the fusion. However, the differences - typically a change in skin coloration and the growth of horns and sometimes a tail, as well as other biological changes - come from both the attributes of the Spirit part and the Demon Primarch chosen during the transformation.