You do need to have enough collective damage to take the ubers out in 8min before the enrage timer hits, I don't think there's a chance of surviving more then a few seconds after that.
As fender stated, having someone pull seige away and keep him busy while the others take down zoltan kuhle first really helps in that fight. In addition to the bubbles, glass canon types need to watch out for the fireballs and rock attacks that zk dishes out as well as those can 1 or 2 shot pretty easily.
For the Ghom/Rakanoth fight, usually you try to take out Ghom first to keep him from stinking up the entire playfield. Sometimes you may need someone to keep Rakanoth busy to keep hom from attacking the other party members as he can 1 or 2 shot as well.
For the Leoric/Magdha fight, you want to concentrate on taking down Leoric first. Again, it sometimes helps to have someone keep Magdha busy on the other side of the field as she spits out bugs and lasers that you can spend more time avoiding than attacking.
I started out the first time by soloing the encounters on mp1 to get the feel for the battle, not necessary and was probably a waste of machines. Then when I started my first group runs I geared more defensively as not dying goes a long way to helping out the others carrying you. And even if you don't have a bunch of damage you can help out by raising others that die. As I got more familiar with what to look for I've started gearing more offensively, just trying to have enough defenses to not get 1 shotted, but on higher mp levels that takes more and more defenses. As a WD your pets also can help by keeping stuff occupied.
Never had to tank ubers so the build I've run is Bola- ID, Echoing Blast, Marked for Death- Grim Reaper, Smokescreen, Prep, Gloom. I only use SS for ubers since its so useful for Kulle's bubbles and rezing people. Passives TA, Perfectionist, Archery/SA.
Thanks. I hadn't thought of using SS, but that makes sense, may have to give that a try as well.
grats!
