Hi guys, I just want to share my humble finding. Thief SB is very effective at copper. You can perma poison with SB4 and tank the bleed from offshoot with SB2 detonation and signet of malice. If you can dodge the boss’s big attacks, it’s very easy to kite while dealing relatively good damage. Maybe you can use S/P for greater damage(I haven’t tried) but poison field for this boss is important in my opinion.
I can kite it solo easily with my berserker armor and 6/6/0/0/2 high DPS build.