[deanjday]

Azor

The dark one, who has been locked away since the war of shadows in the shadow prison deep in the Blighted Waste. The source of all evil in the world and the antithesis of the Creator and the Mother.
An attempt to free him from that dimensional prison at the very end of the war of shadows bought about the tainting of magic, and the shattering of the world. and the end of the age of legends.

He is ever trying to escape his shadow prison in the World Wound and once again enter Solem. He is secretly served by many, especially the teeming masses of Men.

It is said even saying his true name brings evil and misfortune to the speaker.

Behind the curtain
So Azor is the big bad of the setting, very much classically in the mold of evil gods in many settings, but with a twist that he actually came from somewhere else and that not even the Creator truly understands what or who Azor is.
I am taking a lot of inspiration from both wheel of time and Cthulhu and Runequest here in that he is actually physically buried in the World Wound and is actively trying to escape, with many of his servants in a race to free their master and gain great rewards.
This will be a major reason for PC heroes to adventure in the setting, ever on the look out to prevent this from ever happening.