The story line of Heart of Stone is a work of art.
To me it gives the feeling of Stephen King's The Stand but in a fantasy world setting. O'Dimm gives off that Randall Flagg vibe. He isn't a being of any sort but the force of chaos and evil manifested into a corporal form to just meddle in human affairs.
Also his theme song gives me the chills.
https://www.youtube.com/watch?v=kKGmZN06lBI 