Chernobog

Chernobog is a god of misfortune, most commonly sought by cultists, witches, and evil druids. Sometimes called the Wickerman, he likes making deals with desperate or power hungry people. Such deals almost always come at a high cost, usually resulting in the petitioner losing some or all of their soul. Chernobog is the father of vampires, and the origin of the curse of lycanthropy. He often perverts nature, creating undeath where there was once life. He has an insatiable hunger for power, and regularly devours life energies in an attempt to regain his old form.
Before he became known as a god of undeath, Chernobog was a powerful nature spirit and consort of Queen Mab. Called Belobog in those times, he was given dominion over the Council of Beasts, and was the Lord of the Hunt. Belobog was a proud, well loved leader in the feywilds of Aborea, but he craved more. He petitioned the Morrigan for more power and when his lover denied him, he formalized a plan to take it in secret. During his Great Hunts he began feeding on the spirits of the creatures he felled, breaking the cycle of reincarnation the beast spirits enjoyed.
This alerted the Morrigan, who confronted her former lover. Belobog instead of renouncing his bid for power, sought to kill his former lover hoping to consume her power afterwards. He attacked with the aid of his friends, the powerful wolf spirits Lorne and her husband Gorne. Mab retaliated with the Beast Council and Belobog was defeated, much of his flesh ripped away from his once lovely form.
Knowing the powerful demi god could not be fully killed, she instead had Hel, the devil queen, lock him and his wolves up in the Abyss. There he was to stay locked away for eternity, with the demons and other chaotic entities that could not be let loose upon the other realms. Chernobog seethed in hatred locked away here for a seeming eternity, constantly feeding on lower demons in an attempt to gain back his former self. His hunger and hatred was never sated, and in secret he found a way to try his hand at escape.
Chernobog found a way to whisper to mortals in Andorra, and it is he that curses the lands of Mournfall. It is believed he is the first to whisper to Ariem, and that it was his maneuvering that caused the Sundering.
Chernobog is worshiped in cults, as he promises his followers almost anything they desire. In the end the price for such gifts ends up being their or others souls, as he is eternally hungry. He is often the patron of liches and vampires, and he is a lord of undeath. His two wolf spirits are attributed to the spread of the werewolf curse, and it is said wererats are a representation of the pestilence he spreads everywhere, as he now hates everything to do with living nature.
It is believed that Chernobog fused with Ariem during the Sundering. Unlike other such pairings, it seems that the god of undeath took up residence in Estemi's blood, making the first vampire lord. While the god has not extended his will or spoken since this fusing, it is assumed he grows in power the more blood he infects (or the longer his vampires live).