Yhalvia

Yhalvia was an ancient kingdom that was part of the empire of Narfell (−946 DR to −150 DR).

History
The baatezu devil lord Orlex ruled Yhalvia with an iron fist. His reign was naturally cruel, depraved, and wicked.

In time, a band of rebellious wizards arose to depose Orlex. Led by the archmage Thakorsil, they created the throne known as Thakorsil's Seat to imprison and permanently bind and enslave the evil fiend. Unfortunately, although they had the best of intentions, the device demanded deeds of despicable evil to function. Thus, they devised the ritual of twin burnings, which involved the sacrifice of beings of good heart, believing this was for the greater good, that the ends justified the means. They went ahead with the horrific rites, and successfully bound and enslaved Orlex in the Seat.

Afterward, they formed a council of wizards that governed Yhalvia. However, corrupted by the sacrifices and with Orlex as their slave, they soon became as cruel, depraved, and wicked as the devil they had replaced. In time, others overthrew them, Orlex was banished to the planes and Thakorsil's Seat was lost and believed destroyed.

Legacy
By the 14th century DR, Yhalvia was believed to possibly lie on another world entirely,  but had been confirmed to be a part of Narfell in the 15th century.