Perhaps some the creatures contains a clue to the Sage's location, all uncommon updates.
I need to kill the stronger undead in the for clues (a skeletal protector ( 13, -20, -245 ) Copy/waypoint 13, -20, -245, a skeletal lieutenant ( -338, 0, 468 ) Copy/waypoint -338, 0, 468, a skeletal trooper ( -600, -7, 435 ) Copy/waypoint -600, -7, 435)
I need to kill the stronger hawks in the for clues (a puerile hawk ( 706, -1, -698 ) Copy/waypoint 706, -1, -698|).
I need to kill the stronger deer in the for clues (mature antelope ( 184, 1, 1330 ) Copy/waypoint 184, 1, 1330|). (A fledgling antelope also worked)
I need to kill the stronger snakes in the for clues (a plains serpent or a a plains lurker ( 3, -1, 194 ) Copy/waypoint 03, -1, 194|).
I need to kill the stronger crabs in the for clues [ a shore crab ( 1416, -3, 226 ) Copy/waypoint 1416, -3, 226 or a corpse feeder around ( 187, 2, -831 ) Copy/waypoint 187, 2, -831 or ( 348, -22, 144 ) Copy/waypoint 348, -22, 144 ].
The list of alternative sources of quest updates above would imply that any level 22+ creature of the correct type, in any zone, can be killed to advance the quest.