First off, yes I know there are threads about this, but there's something special about this farm that I remember being mentioned but could not find.
The run involves the undead mass spawns behind the cottage in the Gates of Kryta mission.
The secret: killing the first two undead patrols coming to kill the villagers spawns 2-3x more undead.
Second secret: apparently there is a way to make more undead spawn further along the coast, but I can't figure it out.
As for builds, it gets trickier due to the absolutely huge number of enemies spawning.
Builds that I've tried and have worked to a degree:
55 monk with SOJ. Very tricky because you can't overaggro due to the fact that if too many hit you at once, it overcomes your regen. Standard build with 4 maintained enchants, HB, PS, SOJ, BS. One of 2 safest builds.
Cyclone + TC + Live vic + Vig spir + balt spir + bonnetis + dolyaks. Again, difficult because of the large degen caused by poison + phantom pain + bleeding (-10 hp degen) on top of deep wound (phantom pain) and fragility. Very, very tricky.
Barrage ranger with pet (to help kill the first 2 mobs to trigger the larger spawn) and live vic + vig spir + balthazars spirit (put it on the pet) + zealous bow. (2nd of 2 safe builds)
My geo-ele got hurt pretty bad, i think ill try him again with unsteady ground and quake + dstomp.
Any help would be appreciated.
a

. This is the first time you mention 30+ enemies.