Bring an Oracle Crystal to Maurin Bonesplitter in Desolace.
An oracle crystal would do nicely. They are crafted by the naga for their oracles to use.
Northwest of here, along the coast, is a vast coral reef that the naga have taken as their home when this close to the shore. You can find their oracles there. The Slitherblade are deadly and will not react kindly to your intrusions, so be careful and make haste.
When you return, we shall see about finding this demon lord Azrethoc.