God damn, HoR with a pug last night was an immense pain. We had a decently geared Warrior tank, a Blood DK, a rogue, an asshole-specced elemental shaman, and myself (Disc priest). We were attempting the "hide in the corner for LoS" strategy popular on WoWWiki and so forth... and we kept wiping repeatedly on the seventh or eighth waves. Damage was flying everywhere in gigantic quantities.
I had an idea what was going on last night, and looking over the enemy ability set I'm certain. First, there was limited crowd control on the ranged enemies. The warrior (I felt sorry for him) just could not keep everything occupied at once, inevitably leaving the dwarf hunter to stand to the side and use his ranged attacks. I attempted to keep shackle up on him but something (I presume a totem) kept breaking it, the corner-hiding strat made it very difficult for me to pick them up on time, and of course I'm attempting to shackle while playing Turbo Whack-A-Mole with health bars and debuffs.
And that hunter is a big fucking problem if he isn't controlled, because he applies a curse to his target which increases magic damage by 50%, and I can't dispel curses. On top of THAT the rogue mobs apply poisons I can't remove AND they kidney shot the tank like no one's business.
We finally passed it when the Shaman went resto to help with healing... though I don't think his extra healing made the difference so much as he could remove the hunter's curse, and I was free enough to keep casting Shackle everytime someone broke it.
We then wiped on the Lich King portion three times. The first we got WTFpwned by Arthas at the last wall because the DPS didn't burn down that adds fast enough. The second two times two different people disconnected in the middle of the fight and subsequently died. The shaman was spamming his Asshole talents and ragequit- he blamed me for the last three wipes. Apparently I failed to heal through the Lich King's 1,000,000 HP AoE or other player's disconnects.
Another thing... The Abominations in the Lich King encounter spray an AoE/debuff... Vomit something. This was hitting most of the group. Can this be avoided by having the tank turn the abominations away from the group or is it an AoE centered on the abomination?