While arms warriors are generally creatures of the pvp world, most of us at some point in time get involved in pve at least a bit. Many times you will have to tank - it sucks, but often that’s the only way to get a spot in the group. However there are two exceptional instances that came in the expansion where the arms warrior absolutely shines in 5-man groups: Black Morass (caverns of time), and Shattered Halls (hellfire citadel).
Most don’t think of arms as being an AoE class, but effectively that is what we boil down to in pve. The big fat 2 hander with sweeping strikes, cleave, and whirlwind is how we pump out our highest damage. Most of us are spamming MS and Whirlwind even on single targets. Toss in a secondary target and we get more out of our whirlwind and can toss in cleave as another damage boost when rage is in excess.
Unlike a mage, where getting hit while AoE’ing is often disastrous, for an arms warrior its pure goodness fuelling our dps with more rage and enrage procs. While I don’t recommend trying to get hit in most heroics, in non-heroics the damage is low enough that the mitigation of your plate actually makes it not a bad idea.
Why these two instances in particular?
Black morass feels like it was built for an arms warrior specifically. There is NO crowd control involved in this zone. It’s a balls-out dps battle from start to finish. The reason you shine as an arms warrior is that 1 person needs to contain the adds that head for Medivh’s portal - and that 1 person is you. You can grab the trash with piercing howl, keep it next to the elite, and go to town with sweeping strikes, whirlwind, and cleave thus maintaining your dps on the elite AND the trash at the same time.
The main piece you want out of here is [hourglass of the unraveller]. There are also the [pauldrons of the crimson flight] which sadly are worse than [sylvanaar champions shoulders] (or at best a sidegrade).
Shattered halls is home to a lot of 5 and 6 mob pulls. You’re never going to CC them all, so the tank will be holding 2 or 3 mobs (sometimes 4). They hit weak enough that even if you end up with the agro of 2 of them its going to fuel your dps without putting a big strain on your healer. If you take on the adds on the final boss (kargath bladefist) you can again get them close enough to him to be able to whirlwind/cleave damaging both.
There isn’t much in the way of dps-war loot from shattered halls. The main thing you are doing this for is reputation to get you into the heroic hellfire instances. Some goodies to look forward to in those heroics include: [crimsonforge breastplate], [bloodlord's legplates], and [spaulders of slaughter]. There’s also [doomplate gauntlets] which can be good if you’re using them to get the set bonus.
Veritas