Use thoughtlock. Your enemies will be damaging each other, not you, allowing you to fight them at your leisure. In normal, I was using a cataclysm build with SMG's and pistols, but moving into TVHM mode I switched to a thoughtlock build with sniper rifles.
What prompted me to switch was I joined a friend's TVHM game looking to just soak up experience, nab some trash whites for sale, and keep him healed -- at level 31 -- and thoughtlock proved so useful I actually helped him clear from sawtooth straight through to the warrior. My mighty level 36 siren completely trivialized Jack, by thoughtlocking his guardian surveyors.
Sure, ruin paired up with helios does an obscene amount of damage, Surviving happens to be more important, and pairing up a subsequence thoughtlock with helios does damn good damage as well. That's not to mention you can always slag enemies with a slag gun, then switch out to your main damage weapon for the finisher.