I've trained for 2-3 levels on that map as a F/P mage. Just by leaving a poison mist and spamming explosion, the mob never got below two elderwraiths and that was by staying at the left side.
If you stay at the right side the spawn is much heavier and is hard to keep up (more than 6 elderwraiths at a time, can't slow and KB all at once).
Also, the spawn takes a long time to start slowing down, and then you just have to move to the middle of the map and then back to the corners.
Of course that was not at level 120 and instead at level 85-90. so was doing 2-3k per explosion on them.
If you stay at the right side the spawn is much heavier and is hard to keep up (more than 6 elderwraiths at a time, can't slow and KB all at once).
Also, the spawn takes a long time to start slowing down, and then you just have to move to the middle of the map and then back to the corners.
Of course that was not at level 120 and instead at level 85-90. so was doing 2-3k per explosion on them.