just speculation based on the comments in this thread, but he might be using something like this
skills
Shamblers rank 4
Entourage rank 3
Bramble Shield rank 4
Ground Spikes rank 4
Goddess of Thorns (1 pt)
rest in Morale
items
all 3 idols, highest rank you can afford
Gloves of Fell Darkur
Hauberk of Life
whatever else
i've seen that build played before.
summon army at crystal, put up bramble shield. got to open mode. teleport on top of enemy with full army and immediately cast Ground Spikes. the armor debuff will make the minions hit VERY hard for a few seconds.