Dark Speak

Dark Speak belongs to the Aetherium family of tongues. The general survey of the tongues of Erôth gives its usual speakers as demons, devils and evil outsiders, and holds that it is written as well as spoken. It shares its script and its family with Celestial, which the same survey gives to celestials and goodly outsiders.

What it is used for in Erôth, and by whom, was never written down.