So, in the process of farming keys for my Hellfire Ring, and Act 2 is giving me a LOT of trouble. In short, getting raped very easily by a lot of mobs, whether it be the ones that move insanely fast, or the ones with stupidly-high-damage projectiles that also move insanely fast, or whatever. I can farm Act 1 MP5 very easily, but Act 2 I'm getting my ass handed to me just trying to build up 5 stacks. (to get the keywarden to drop a key)
tl;dr: What's the easiest place to get 5NV in Act 2?