This mission took me 2 attempts. The first was incredibly lousy luck. Most groups comprised of eles, mesmers and monks. Even with prot spirit in the party I found myself getting DPed out due to massive spikes and pressure from the mesmers. I actually made it to the last NPC thanks to a few rainbow CCs I had on me at the time. Still with 20% DP on each hero I went in only to trigger the NPC at that god forsaken rock and receive massive hatred from x2 eles, a mesmer and a roj monk.

The Second attempt was a joke. Most groups comprised of sins, warriors, rangers, necros and rits with the occasional ele, mesmer and monk. The final afflicted group was easily pulled without triggering the NPC.
My 2 cents... its still an irritating quest and it still boils down to luck. The only difference is you wont rage for spending the last hour recovering from wipes, being cautious and doing precise pulling.