Talk to Maurin Bonesplitter.
The torn skin smells rotten, and is remarkably pliable for something that appears to be dry and fragile.
As you unroll it, you can clearly see the red markings of some kind of language on one side. At the bottom of the skin is a very clear symbol that you guess is a signature of some kind.
Perhaps it is something Maurin could tell you more about?
The Burning Blade begin to realize how weak they truly are. Their magics are pathetic, their strength feeble.
Their only power comes from those they serve, and not from any understanding of true power and knowledge.
Hmm, these runes are indeed a language, <Name>, an old language. They seem remotely similar to the Eredun language, but the differences are drastic. If I am not mistaken, this is a contract of some kind.... Here, yes, this symbol is the demon's signature: Lord Azrethoc.