chatdemon writes "Few folk dare to whisper the name of the lord of the undead, much less tell his tale. But for those of sound faith and curiousity, here is one version of that story.
The Story of Kyuss
By: Chatdemon (firstname.lastname@example.org)
(Used with Permission. Do not repost without obtaining prior permission from the author.)
Olandra, a Cleric of Nerull working 'undercover' in Zeltra (the central town of the Jasidan church structure in the ancient Suloise empire) had become frustrated in her attempts to ferret out information for her dark masters (the church of Nerull in Vecna's empire to the east) by infiltrating the Jasidan church hierarchy.
Quite simply, she lacked the faith and devotion to learning the Jasidan way to reach the ranks within the church that would grant her access to the secrets that Nerull's clergy were seeking. She found that by seducing (literally and figuratively) the young and talented cleric Asternin, of the little known Eowen house and offering him access to knowledge beyond that of any of the temple libraries, he was more than
willing to take wine with her and spill even the most gaurded secrets of the faith.
In exchange for becoming Nerull's eyes and ears, Kyuss  became wildly powerful and influential in the church, and succeeded in overturning the canon law that forbade dabbling in the art of necromancy. (These laws have since been reinstated by the Jasidan church, but the damage is done, as much of the lore uncovered during Kyuss's time is still floating around for mortal wizards to play with.) He and Olandra presided over what is known in Suloise history as the 30 Year Nightmare, wherein the towns of Zeltra and Zinbyle were plagued by undead and other vile monsters, and necromancers and corrupt Jasidan clerics terrorized the northeastern reaches of the Suel empire.
The pinnacle of Kyuss' dabbling in Necromancy was the creation of the Dreaded Sons, but this was also to be his downfall. The first batch of true Sons of Kyuss went about terrorizing and ransacking the town of Zeltra, eventually coming upon the Hall of Shining Echoes, the temple of Lydia that housed the Sun Maiden sect of Lydian Paladins (see my article on the Suel relic Lightbringer for more information on the Sun Maidens).
The clergy of that temple lost more than half their numbers destroying the abominations, but afterward, their leader, Sabien, rallied them into
storming the Ruby Palace (Wee Jas temple in Zeltra) and defeating Kyuss and Olandra once and for all. Late that night, after a bloody battle through the halls of the Jasidan temple, Sabien herself wielded the holy spear Lightbringer and slayed the now insane necromancer as he attempted to channel the power of his Goddess, who had become disgusted with his heresy and denied his pleas for divine aid.
Olandra was spared, for she lied convincingly and claimed that she was a mere student of the magical arts from the eastern empire who had been forced to serve Kyuss against her will. She was taken to the Kendeen Pass, given a week's rations, and told never to return to the Empire again, but she was spared. Things slowly got
back to normal in Zeltra and the surrounding countryside, and the name of Asternin of Eowen was eventually forgotten by the Suloise people.
But not by Nerull.
Pleased with Kyuss' performance as a necromancer, but concerned about his misplaced loyalty, Nerull intercepted Kyuss's soul as it travelled to the Halls of the Dead in Wee Jas' celestial palace. Nerull revealed Olandra's
treachery to Kyuss, who was outraged and dismayed at his lover's duplicity.
Nerull told Kyuss he could grant him vengeance on his betrayer, but that it would cost him dearly, as he would be ever forbidden entry to the Halls of the Dead. Nerull explained though that should Kyuss accept his offer and show his loyalty to a new master by having his vengeance not only on
Olandra, but also on Sabien and the other Sun Maidens, then Kyuss would sit beside him in his divine palace, and rule all practitioners of necromancy on Oerth, forever.
As history has shown, Kyuss accepted the offer and returned to Oerth as the first Revenant, stalking and killing both Olandra and Sabien. After killing the Lydian paladin, Kyuss set the Hall of Shining Echoes ablaze, and set off for the eastern empire, to report his success to Nerull's clergy there and bestow the holy spear Lightbringer, which he had captured, upon their church. Howerver, he never set foot east of the Crystalmists.
Halfway across the Kendeen Pass, Kyuss was confronted by the Solar Mikarli (an ascended Sun Maiden Paladin, the highest servant of Lydia, and a hero-goddess in her own right), who destroyed the creature and retrieved the spear. Kyuss had, however, fulfilled his end of the bargain, and was
rewarded with his own ascension to divine status, where he has remained as a dark patron for those who dabble in necromancy and undeath ever since.
Kyuss and his clergy are despised by Wee Jas' church, who attempt to capture them and try them on charges of heresy against the Suel Pantheon. This usually leads to a quick but formal execution.
The usually mild mannered and peaceful followers of Lydia (including and especially the Sun Maiden sect in the modern Flanaess) are not so kind as to
grant Kyuss's followers a trial. Anyone displaying or professing loyalty to the dark godling or his faith are attacked on sight and killed.
 Kyuss is a title/nickname, from the Suel phrase kyut suss, meaning "defiant outcast. (This phrase is also the source of the Suss Forest, the "Outcast Forest," named so by the Keoish early in the reign of that kingdom for the fact that many undesirables in the Sheldomar Valley and Lortmil Mountains were slowly driven into the Suss Forest and the Pomarj.) It has become a heresy punishable by execution by fire to utter Asternin Eowen's true name."