Ill omens were all around the Inconnu who sought to defeat the usurper, Morgana. The battle for the souls of Annwn had grown to a feverish pitch with the surprise attack that Morgana dealt those faithful to Arawn. The witch had possessed a large force of the Inconnu and turned them upon their brethren, dividing the race in two, causing great strife in the lands of the dead.
Cysgod was a scholarly Inconnu necromancer who researched long and hard for a method to combat Morgana, and to gain the upper hand in the ongoing war. Through his questing and study he ventured to the lands of Camelot and Atlantis and discovered that Arawn was not the only god of the underworld and the dead. He found that there existed other such gods named Hades, Hel, Osiris and many more who also claimed rulership over the domains that his own god Arawn declared ownership of. His journeys abroad led him back closer home to where he knew the human Arawnites had once kept a temple to his god. There, beneath Camelot, he found the remains and tenets of yet another god of the dead, Pluto and his plutonists. Cysgod marveled at the work done by the plutonists and found himself appreciating the combined religion that Aulus, the high priest of Pluto, had created honoring Arawn, Pluto and other similar gods of the underworld.
Cysgod kept the knowledge that Arawn was not the only god of the underworld and the dead to himself for a time for fear that the other Inconnu would label him a traitor, heretic and madman. Eventually however he consulted with those closest to him, other Inconnu who shared his scholarly interests and who also endeavored to defeat Morgana. In time a small cabal of necromancers formed of those who came to terms with the information they had found. They took the next step, together, with a scattering of other indoctrinated death worshippers from the Temple of Pluto, to uncover the next step past such knowledge.
Cysgod and his extremely secretive cabal came to the determination through their combined efforts in research and theorizing that there was a higher force of nature that these gods themselves served. Many names were bantered between them for this higher and darker power â€“ the Shadow, the Void and Oblivion just to name a few. The cabal came to the realization that perhaps their best strategy in finding a weapon against Morgana was to beseech this entity or force for the aid they would need to free their kin and secure their homelands.
A great ritual was devised by Cysgod deep within the Aqueducts and the Temple of Pluto, where the Shroud between the land of the living and the world beyond was almost non-existent due to the centuries of worship to the deities of the dead, the cabal conducted their dark rites to call attention from the Void itself.
The ritual worked, perhaps entirely too well as a great Darkness answered their call and descended upon them, blacker than anything they had experienced before in their crypts and underground lands. This unholy and cold force devoured Cysgod and his cabal entirely, yet the majority of them did not cease to be. Most were reborn into extensions of this Shadow and acted as its agents, hating all life, energy and warmth. Even the kin that they had at once sought to save were nothing but objects of their intense hunger and hatred. The Tenebrae had been born, and they began to spread out from the Aqueducts into the varied caverns and cities that they used to know as home. All that they defeated by their hands were reborn in their image, as warriors and servants of Oblivion.
The Tenebrae, growing in number rapidly, attacked both former friends and foes alike and wanted nothing more than to satiate their overbearing hunger to consume the lands of light and the realms of the living.
Those Tenebrae who were once Inconnu retained much of their knowledge from their former existence. There were those who remembered when Arawn commanded the Mines to be re-opened and knew how to find the entrances of the once Abandoned Mines. These Tenebrae recalled an energy about those Mines, found in the form of crystals, which at once both repelled and attracted them. They sought to feed upon this power and taint it, to convert it to their own dark ends. The living shadows descended upon the Mines like a plague, finding both their former brethren and other creatures that further sparked their terrible thirst.
After much fighting, the inhabitants of the Mines have found themselves in a losing battle, as each individual they lose to the Tenebrae rises again as extensions of the Void, fighting their former loved ones and allies. Gnolls, Half-orcs, Inconnu and more are being pushed slowly into the corners of the Mines as the Tenebrae siphon the energy out of the crystals, changing it into entropic power that they harness for an unholy cause, to bring Cysgod from beyond the Shroud so that with his might and guidance they can march upon the Crypts of the Inconnu, the Deadlands of Annwn and the realms of Albion.