Lord Vanrak Moonstar was once a minor noble of House Moonstar of Waterdeep and a noted explorer. Corrupted by Shar, he later became a death knight who led a large cult of Shar known as the Dark Army of the Night in Vanrakdoom, part of the vast Undermountain complex beneath Waterdeep.

After his transformation into a death knight, Vanrak largely occupied himself with expanding the influence of Shar and skirmishing with the followers of Selûne in Waterdeep.

Vanrak's greatest success came in the Year of the Tomb, 1182 DR, when his forces infiltrated and burned down the High House of Stars and slew the Moonmaiden's protectors.

He befriended a former bronze dragon, Glyster (transformed by the priests into a shadow dragon, who took the name Umbraxakar), who served as his companion, guide, and mount.