Dislocating monsters is some kind of error/bug. As soon as player pass near them they teleport to original location. No need to hit them or something like that, just stay close. For this exp spot only logical place they can hide the mobs is south near mountains. Such act require more efforts than undo it. Put a cam when/if you find the mobs and bingo - mobs will be back. In hour or less I will check the situation and if they are still bugged - will set them free Other logical location for monster bug is btw Massacre and Seal of Shilien. But many players with wars pass by those roads and if they come in contact with monsters they should teleport back.