I've found some information about the game's world and backstory here and I'm curious as to where you got it.
I've owned a copy of Brutal Legend ever since it came out and have played it many times. But in all these years I've never known what Lionwhyte and the Coil were getting out of the mines or Ophelia named the Drowning Doom after what happened to her parents until today.
So how is it you know? Was it mentioned in the art book? In some other official text? Or did I just miss something in the game? Because I'd hate to think you are just making it up.
By the way, I love this game and it's lore but, I think you'll agree, it's delivery of backstory and world building could have been much better.