***SPOILER***
*
*
*
*
*
*
*
**
*
*
*
*
*
*
As Lord Shield stated, it is in the Sanghuin City. However, if you did not accept Saemon Haevarian's offer to take you home on his ship, you would not have come across the City. If you are/were there, you need to walk on the large platform in the middle of the city that looks like it is inside the mouth of a big-ass fish. You will trigger a battle when you step on it. You'll pick it off of a priestess's corpse, if you're lucky...
------------------
Now where did I leave that doughnut?!