Iaurlum is a demon of Donere, one of many who served the Abyss during the Second Age. Like many of the ancient demons, he was cast into the deepest reaches of El-Bayir following the War. He slumbered for millennia, and the Dwarves unintentionally built their great citadel, Mel Badhir, above him. As they mined, they dug deeper and deeper, eventually rousing Iaurlum from his slumber. In a period of great crisis, as the Dwarves found themselves beset by exterior foes and internal politics of the Empire, Iaurlum swept through the citadel, killing thousands. He used a great deal of his power to drag the citadel into the earth, burying it for centuries. He still resides in the citadel, waiting for any traveler who may try to cross his path.
Stat-wise he will either be a glabrezu or a nalfeshnee