The tunnel phase is pretty easy if you send mages in there. All of the mobs can be sheeped, so only one tank and one healer is needed. If you're not too worried about getting the hard mode, you could probably send only 4 or 5 DPS in the tunnel and still make due. Last night we also found that the enrage timer for reaching Thorim is 6 minutes, not 5 as DBM is showing.

The top seems way more likely to get overwhelmed. The only 'hard' parts of the tunnel involve not getting hit by Runic Smash (think Utgarde Pinnacle - Left side or Right Side) and when you get to the second Miniboss, you need to run away from whoever gets the debuff (DBM marks a Skull on their head).

The top phase can be done with 1 dedicated Single target tank and one dedicated AOE tank with the whole raid stacking on the center of the arena. As the above posters pointed out, single target DPSing the Champions down quickly helps loads, as the other mobs do not hit very hard nor have very much HP, it's quite feasible to have a tank holding several waves.

Having the whole raid stack in the center also helps for avoiding the Lightning damage. The 4 towers with orbs on them will periodically start channeling a nature damage spell on somebody and it 'arcs' to nearby players, but the range seems to be fairly small and it never hit people who were standing in the middle.

Wow. Is that "intended"? May be worth reporting on official forums.

Why wouldn't it be intended? It's a defense-reduction debuff after all.

Thorim's chain lightning casts are somewhat predictable, actually. Melee can spread while he's absorbing lightning, losing 5-6 seconds of dps time on average. Are you saying this because of dps requirements, or because in hard mode chain lightnings don't follow a pattern?

DPS requirements, the more movement the less DPS so the more people you can get in melee range to avoid having to move from blizzard the better. Could have rangee in melee range stacked on each other but ends up being better with melee due to AOE damage reduction and more HP in general. As well, whenever people have to move is when people will most likely get too close to others (oh the fun of coordinating movements in hectic situations).

Pretty sure the chain lightnings were more common than the charges so not sure if they really have a pattern, but I can't check logs at the moment to verify (seem to recall my addon was spamming to raid chat a chain lightning path every 5-10 seconds whereas the charge is every 15 seconds but wasn't trying to look for a pattern so maybe there was one).

Yeh forget me, should put brain in gear before posting.

So, we have put in a few attempts on Thorim, I was wondering with the raid stacking up in the center for the arena part how do you deal with Stormhammer (especially the 75% slow cast debuff)?

The stormhammer didn't really seem to cause any problems for us in the arena. The healers in the arena are usually spread out around the melee about 5-8 yards away from the center area so only one gets hit at a time. The slowing debuff itself doesn't last very long and when other healers get the debuff I try to pick up their slack (myself being a resto druid). We didn't assign anyone to disarm / stun or assign tanks to anything in particular. I basically told the tanks to just pick everything up and for the melee to aoe (we had two rogues, one assigned to each tank for fan of knives tricks of the trade which helped tremendously).

I think our gauntlet group had 10-11. 2 tanks, 2-3 heals, rest dps. Arena had 2 tanks, 4 heals, rest dps. Dps were separated via physical and magical like everyone else.

I think the most important thing aside from having good arena tanks was quick reactive heals in the arena. The melee group would tend to lose 50-60% of their health at a time from whirlwind, and healing that up quickly / covering tank healing when other healers were stunned won it for us I think.

Some nice points here, thanks guys, we have the gauntlet / arena phase nailed down now . . . arena team clump up, single target down elites and aoe the rest, out composition for those interested was:

Arena - 2 tanks, 4healers, 9dps.
Gauntlet - 2 tanks, 3healers, 5dps.

Now we reached the final phase with thorim in the arena a few times but it seems alot harder than the "phase 3 = kill that I have read". I think our DPS is just too low, does anyone know how many stacks it takes before your tank will just be unhealabe (this is the stacking debuff on thorim NOT unblancing strike im talking about), looking for some idea of a timer in which you need to of killed him. Guessing we could cut down on 1 tank and 1 healer to boost DPS, thanks for help.

The soft enrage with the stacking debuff doesn't seem too rough to me. If anything, chain lightning will be ripping your melee apart before the tank(s) become unhealable.

The guy's got 15 million hitpoints and with 14 dps (which is admittedly low) doing ~4k each (again, low) it shouldn't take you more than 4 minutes to kill it. Thorim phase 2 is almost as static as Patchwerk.

How long are you taking on the gauntlet? Do people die?

Has anyone else noted that the Adds in the arena seem to always go to the person furthest out from the center? There is definitely some strange mechanic at work. I was testing it last night and it seemed the more adds that were on the floor the less likely they came to me or the other tank. Incidentally we tested this outside the ring theory with a healer, mage, and tanks.

Furthest person from the middle (or ring in the middle of the floor) had the new adds pathing straight for them regardless of player class.