Solo'd these since they can be snared/rooted and do not summon. They move fast though. The key is to snare them and kill one while keeping the other one in LoS. This is because it will despawn if not aggro'd soon after spawning. If that happens you can respawn them as explained in the quest writeup but you will need still to kill 2 of them. In other words killing one alone and then losing the other to despawn is worthless as you get no credit for the 1 kill.
The entry above "aggros even when grey"... considering the mobs are level 105 and grey to no player in the game how do we know this? Just wondering...
Edited, Feb 7th 2018 4:20pm by Sippin