Xichev'Drolough
A clever and once-influential demon who fell from favor of the darkest demon lords and was thrown from their midst, Xichev'Drolough has for ages attempted to reclaim his position among demonkind. He has brought about many hardships and cruelties in the land, but his most noteworthy is his subjugation of the srryn and Nordath folk. Through trickery he caused the srryn hordes to assault the barony of Nordath, in the time of the old republic of Earendam. Even more deceitfully, he caused the templar knights of Nordath to swear their souls upon his own black heart.
PCs who work to liberate the phantom knights from Xichev'Drolough's curse will confront the demon. Even if he is cut down, he places a curse -- if asleep at midnight, the PCs will see his eyes.
He may be used for more mischief in the future.