Use Sablemane's Signet at the Altar of Goc, then kill Goc.
The time has come for us to face Goc, the master of the Bladespire ogres. It is also time that I take a hand in events, to see the last of the gronn's life.
Take my signet ring. When you come to the Altar of Goc, use it, and I will come to join you.
Together we will destroy Goc.