The location the Divination leads you to is different each time you zone into Arbor Bay. The proximity indicator will fill to indicate you are on the right track, initially blue, and turning to red as you get close. Once the indicator fills completely, the Facet of Spirit will spawn. See the Facet of Spirit section for possible spawning locations. Note that it is possible to get an indicator filled around 90% when entering Arbor Bay from Vlox's Falls. The boss should not be much of a challenge provided you don't accidentally aggro a nearby group.