I failed a month ago on a slightly different build. I came back, finished it in 15 minutes without pots. The winning factors are simple: you must kill fast and you must keep moving. This quest is designed for zerging, and that's where my build shines.
It's one of those rare occasions where the Epic robe of dissonance is golden, and where you need quick fingers, the sonic damage dealt by the scorpions at the end is insane.