Khaori Empire

The Khaori Empire ruled civilized Sycharia from 953 to the advent of the Ash Fall cataclysm. After the fall of the Yuan-ti Xitalian Empire and the ascension of the beings that would become the Doheaga Pantheon, the wood elves and high elves allied with the drow of the Underdark below the Brighdeen Mountains. Their empire lasted through a classical era of peace in the first 500 years but devolved into legendary debauchery in the latter half of the empire.  The 9th emperor, Malhethyn the Undying, sought to replicate the ascension of the Doheaga and spent nearly two centuries searching for the pieces of the Stave of Ischarlin.  In a bloody act of slaughter, he captured 10,000 descendants of the Ischarlin shamans and used their blood to power the stave without the use of the final piece, the Binding. The act, which was orchestrated by an alien intelligence called Grosh al' Dryn, opened a hole in the multi-verse allowing the being to enter.  He along with 11 other despots and tyrants known only as the Nameless were all destroyed.  The Khaori Empire was completely decimated in the cataclysm.

The acts of the final four living Primal Champions in concert with the Ischarlin shamans caged the Blood King in a prison powered by their alien technology melded with the fey essence of all elves in Sycharia.  This prison causes the curse on all Sycharia known as The Gloom.