Hey stealth thanks for the guide! Just wanted to throw in my 2cents about how to deal with ULTRA stone 4 kab quest.
Unfortunately not that straightforward. Would be to craft a tantrum bow with high phys dmg and CB. A wdm proc if possible or ttad too if that can even show up on bows..P.rainbow stones.
Tantrum all the minions to hell, and then run in a tight circle around the boss making tantrum blasts.(think lc0 but instead of a lazor its a never-ending broadside machine gun...and no statues) This takes some practice to get the timing and approach right, but kills him quick once u have it down.chug Health pots as you run in. You can try casting scourge on the opposite side of the boss from you to get him shooting in that direction allowing you to run in. Its tricky though.
The broadside hurts a LOT so if you get caught you will probably die. Having some teleport on being struck, or if you have Hellfire Plate rw the blink on taking dmg can save you too. If you think you're about to die try to run away u might be able to recover corpse for another try
lots of DR, vit, maxed defensive and stat skills. Super beast ofc. Sry that got long, hope it helps somebody