I was in The Feerrott last night experimenting with different ways of fighting solo. I'm a lvl 34 Warlock. I had read a few times on these boards that people use both Paralyzing Fear and Frozen Manacles to get the job done. Well, I decided to try it and wowzers, I hardly ever get hit and the mobs only take a bit longer to go down. I believe the total risk vs reward equation would actually favour this method as there is practically no risk (mob resists one of the roots and comes at you, stun it down and cast the next root that should already have ended it's timer). I have yet to try it out on a ^^ Green Mob. I tried a ^^ Green Mob before I had read about using this combo (it just never occured to me to try it) and I only got it down to 3/4 health before I had to break encounter and run like heck.
