Just ran across this leveling my new main, dinged me over to 84.
This NPC corresponds to this quest, but you don't have to have the quest to see him. Occasionally he will spawn in the quest area as an 84 Elite.
Despite being an elite, he is fairly easy to kill as a 83 Rogue in quest gear, so I think this might be some sort of bug. Killing him nets you a clean 150k experience points for minimal effort, and it is repeatable, thought I'm not sure how long his timer is. I just revisited the area without finishing that quest throughout my leveling in Uldum for a boost to my XP/H.