If you can manage your way up to Izual in inferno and bring him down you open up a waypoint to spire level 2 where you can easily EASILY kill the NPC spawned purple mob as a DH. Just lay a bunch of traps before it spawns and she explodes upon spawning.
Some say "well killing Izual in Inferno is pretty hard" wrong! (if you're a ranged

)

If you position yourself behind this crystal with a boneweave (only takes one) blocking his path, he is out of your line of site thus meaning his frost nova and his frozen thing will not ever hit you.
WARNING: I recommend getting the hang of this on normal or hell because if you die during the encounter with your boneweave on the floor YOU WILL LOSE IT!