Shatterbone the Forsaken Warlord

Strategy
To spawn, clear groups of skeletons around the big tree (the skeleton groups near the edge of the water may need to die too.) Next, clear the 5-6 new skeleton encounters that pop closer to the tents (battlepriests, soldiers, scouts.) Finally, Shatterbone pops with 6 heroic forgotten vanquishers (level 63, all separate heroic encounters.) Be careful of the roamers that continue to pop when you're doing this.