Daleen became the reigning Laird fifty years before when she murdered her father.
In the late 1480s DR, her consort was captured by the fire giants of Maerimydra. She led a raid to free him but with no success. Daleen however stole many treasures from Hledh Hellspawn's lair. Among them was a samovar modeled like a marilith. She drank from it and was possessed by the demon lord–inflicted madness, which soon spread to all the city.
Daleen remained in her throne room assisted by the succubus Ashroot until an adventuring party, hired by Elanil Elassidil to investigate crazed duergar, arrived in Zortagra. Somehow, the adventurers stopped the spread of madness by taking away the samovar.