Make it more appealing to kill. The boss mob should drop one unique item raid level. Something equivaent to what you see on the Capital City merchants. Have it spawn at a certain minute mark of the task, so players redirect their attention towards it. Announcement that the boss mob as entered the zone. It should be a bigger part of the realm task. You have players running TG, Sidi, and Galla all the time because of the feathers, so perhaps they can go after this Boss instead. Perhaps there will be battlegroups of PvE players that just focus on killing the boss during a task.