Scout Eldyum must be spawned. This is a 3-wave ring event. Stand near the griffon station end of the Village of Thundermist. Start the ring event by walking on the rock nearest Defender Bolaris/Defender Rowan at ( 604, 6, -163 ) /waypoint 604, 6, -163. After the third wave the scout will then appear among next to the rock you walked on to start the ring.
You no longer have to kill (or even attack) the third wave; you may allow the guards to take care of them. The scout will spawn after this mob is dead.
Scout Cendalya can be found on a rock ledge at ( 1410, 0, 308 ) /waypoint 1410, 0, 308.