Quote from Robb_Starkfor ubers:
bola shot - imminent doom: seems to be the highest damage hatred generator
cluster arrow - cluster bombs: for ubers, it hits 3-4 times. forget impale which only hits once with big numbers, cluster arrow works better, not to mention it goes through enemies. when i go for ubers with my usual party, cluster arrow ticks 4 times at 800-1.2m dmg per tick.
marked for death - mortal enemy: hatred generation to make you able to spam cluster arrow fast
shadow power - gloom: i usually hold rakenoth solo while the rest of the party goes for ghom. this is possible only because i have almost perma gloom
preparation - backup plan: disc source
smoke screen - lingering fog(optional): the only uber that can 1 shot me even with gloom up is maghda's butterly homing attack and kulle's meteor hit. it's easy enough to react to and use smoke screen to avoid getting hit.
steady aim(you don't need to faceroll ubers, you're usually at a distance anyway
archery(50 crit always helps)
night stalker(for perma gloom for bosses like maghda or ghom/rakenoth and sigebreaker)
I'll definitely be giving this a shot. My only concern is using Cluster Bombs. I know Cluster Arrow hits like a truck, but wouldn't you have to be right in the face of whoever you're shooting in order for all the bombs to hit? The shot moves so slow and has such a short range, which conflicts with Steady Aim.
Quote from DiegoFBola shot - stun = Works great for all bosses
Spike Trap - echoing blast - Great Damage overall
Shadow Power gloom
Sentry - spitfire for ubber damage ou guardian for more resist
preparation - backup plan
Marked for death - mortal enemy
Archery/perfectionist(you may change to night stalker)/custom engineering
This is similar to the build I was using before. I discovered having Spike Trap/Echoing Blast under the boss at all times does some serious damage. The only problem is if they move then I just wasted a whole orb of Hatred. Usually it's not that big of a problem, just not desireable.