Many overlords embody something that is feared; Val Gultesh feeds on fear itself. It thrives on paranoia and on lives torn apart by unfounded fears, and crafts nightmares that help spread terrifying and disruptive ideas. While it can shape nightmares, it does so from Eberron—effectively using a powerful form of the dream spell that can potentially affect hundreds of people at once—as opposed to entering Dal Quor. The quori of the present age haven’t encountered an unbound Val Gultesh, but it’s quite possible the overlord would pose a threat to them, especially to quori manifesting in Eberron as Inspired or kalashtar. Val Gultesh is imprisoned somewhere in Zilargo, and it’s possible that should its power grow, that it could corrupt the Trust to serve its purposes; however, the Trust could be aware of this threat and may have ruthlessly eliminated cults of Val Gultesh in the past
The Shaper of Nightmares works with the Lords of
Dust, but the nature of its speaker and the power of its
faction have yet to be established.
Source: Chronicles of Eberron