The Dark One
Always associated with the “Dark” aspect of the Light/Dark duality, the Dark One goes by many names – Soul Blighter, World Ender, The Tainted One, Shaitan, and many more depending on the culture and region. The Shadow Sold commonly refer to the Dark One as He-Who-Watches or the Great Lord of the Dark.
Whatever you call him, the fact remains that the Dark One exists solely to pervert and destroy all of The Creator’s machinations. A thousand years ago a group of powerful Wizards called the Dark One from outside of the world physically into it. The resulting wars and devastation that ensued has become known as The Breaking of the World.
Since then, the Dark One’s influence has leaked out of his sealed prison, creating more DarkSpawn, and influencing more of the Creator’s children to serve him, turning them into Shadow Sold, and on much much rarer occasions – the horrific entities known as the Neverborn.
Philosophically, the most important distinction between the Dark One and the Creator is the fact that the Dark One is said to be completely unable to create new life on his own. He is only able to alter what already exists. This is apparent in the Neverborn, but what that means for Darkspawn can only be guessed.