This has been discussed in the Heroics thread off and on, but that thread is rather large/unwieldy and this trial is, I hope, worthy of its own topic due to the difficulty level. It is this trial in particular which makes keying a guild for TK a logistical feat; the others will be done by players coincidentally, but this one will only ever be done by players who are striving to complete it.

This trial is extremely difficult to one-shot as learning wipes are inevitable due to the complexity of some of the pulls in Halls and the erratic behavior of the two later bosses. CC of one form or another (I've done it exclusively with fear, and in a fear-free group with a rogue and mage) is a necessity, DPS is important, invuln pots are a valuable tool, MC/seduce are (currently) near-useless, but overall group composition is somewhat flexible. Solo healing it is an absolute possibility as the instance is largely a test of dps and control; there is virtually no spike damage and tank healing is relatively easy for a heroic.

The pulls are simply a matter of practice, finding out how your group handles them best. There are a few things you need to know:

Legionnaires, Reavers, and Heathens are the only mobs that will hit a tank for significant damage in heroic. Sharpshooters have an extremely powerful viper sting which will cause healer mana to evaporate. There are two hallways of legionnaire pulls; in the first one, killing a mob before a legionnaire will summon a non-elite Fel Orc Convert, in the second one, killing a mob before a legionnaire will aggro a much nastier Reaver.

What I really want to discuss, are the bosses.

Warbringer Omokk is some combination of untuned and poorly designed, and appears to be bugged and will hit significantly harder on future attempts if you wipe (some sort of enrage? or part of the fire buff stays permanently). Nobody's figured out how his aggro mechanic works, if it works in any non-random manner, and the fight is just a dps burn assisted with a little kiting, a few invuln potions for dps without any other defense, and a little luck. Don't try to control this fight, it's not possible, just heal through it and burn him down.

Kargath Bladefist on heroic is extremely melee-unfriendly. He hits the tank for the same miserably low numbers, but the adds are stronger and his blade dance does double damage. If anyone has successfully killed him with two melee dps, I'd like to hear about it. If melee wants to survive they need to time the blade dance and run away from the tank, as a blade dance while he has sweeping strikes up will cause ridiculous amounts of damage as it chains like the old WW-SS combo. (I doubt this behavior is intended, because SS+blade dance does absolutely hilarious amounts of damage. Cloth will literally instantly die. Spread out C'thun style.)

Even if melee dps successfully survives they will spend a lot of time evading his attacks and as a result do the dps of a wet noodle, and thus are probably better off on add duty. The ranged adds on heroic also have the ultra-viper-sting and thus cannot be ignored in a full-out dps burn unless your dps is excellent. A bad blade dance can still deal over 10k damage to cloth, but since this is over the course of a few seconds heals should be landing before people die.

As an enhancement shaman I am extremely glad that I can put on healing gear and stand at 40 yards in heroics as necessary. Sweeping Strikes and 360 degree cleaves need to go, NOW.

I (holy Priest) did it today with a Druid (feral), Paladin (holy) and two Mages (deep frost and arcane/frost). With that amount of crowd control, the trash wasn't a problem ever and with 2x2x iceblock + limited invulnerability potions, the last two bosses weren't a problem at all. You would think dps would be a bit low with that kind of setup, but I think we killed Kargath in around 45 minutes with 3-4 wipes on the way (1 to Kargath, the rest to trash).

The conclusion that I make from that is that high dps is not super important. If you just pull fast and drink a bit after every pull (only drink to full on the really big ones), you should easily be able to get by with two main healers. Remember again that the executioner uses a new ax for each prisoner, it's only that quest that gives 25g that has to be done in 55 minutes, so you have plenty of time.

As for the melee issue. DPS warrior... just say no. No crowd control and just as vulnerable as a rogue to Kargath's blade dance (more armor, but no dodge or evasion emergency button), and speaking of rogues... You will probably only ever do this once as a rogue, so it might be worth it to respec into improved sap for this one occasion. Yes it sucks, but you do what you gotta do, right?

One thing that I've been pondering though is what's the best main healer for this place? Priest worked OK for the really big pulls since I could use fear, but man am I squishy. And not being able to remove that Viper Sting when I get it (shit always happens, so you gotta plan for it, right?) is pretty annoying.

My best guess as to Warbringer O'mrogg's threat mechanics is that he simply resets the threat of whoever currently has aggro to zero (or possibly whoever leads the threat list, accounting for aggro thresholds). I'll have to run it with a group where everybody has KTM to verify that theory, though.

I'm not sure how that could be turned into a viable strategy for him, though, unless there is a way to force the deaggro.

I've had very good success with having an OT save up rage for after the first deagro O'mrogg does and just generating as much threat as he can after that. He usually switches to either myself or the OT for several switches after that... only coming off sub 10% when we just burn him.
I've always had two tanks for my runs and we all brought invul pots as well and it was never a major issue.

I could swear that someone had theorized it as being an aggro table reversal (first gets last place aggro, last place gets first place), and their evidence was that a feigning hunter could reliably get aggro after the swap, but I can't find the post now.

it's just wrong, tried some things like that, he definitely does not go for lowest aggro. I've finished the trial and the 55 minutes quest twice now with different groups. We tried to learn what the ogre really does, but gave it up after a while. Both groups I did it with had a Paladin and we brought Limited Inv Potions. First aggro swtich got BoP'ed and after that we used pots, if he switched to a cloth user. It shouldn't take more then 4-5 switches at worst and with good dps, you can get him easily down in three.

For Kargath we did two different things. Once the group had a tank and a rogue, so the rogue just stood in the entrance area and killed adds and the other dps, a lock, helped him out if he needed to catch up. That meant it turned into a fairly epic fight, but healing was np with two healers.
The other time we had tank, pala, mage, lock, priest and lock/mage sucks for the adds. That time we tanked him close to the bridge and the warrior picked up the spawns. The first 3-4 both casters zerged them down, after that we ignored them, the warrior tanked them and we feared a bit and just nuked down the boss. That plan is much better imo, Kargath doesn't have that much hp and he dies fairly quick, even with two healers in the group.

Spoiler: How to attune slackers.
The trial is finished by killing a lvl 70 trash mob behind Kargath. Given that most guilds only have 3-5 good tanks, some more good healers and a lot more dps, it will be difficult to find good groups for everyone if some people don't go again and again.
Well, the way the trial is set up you can easily 'exploit' it. Clear the dungeon with a good group (did it in less then 45 minutes both times and even if you don't do executioner yourself, you get 4 badges from that) and then leave after Kargath and let five people needing the trial get in.
The executioner for the trial is a lvl 70 elite trash mob. He doesn't hit hard at all, he has low hp, you don't even need a healer for that dude. So you can always attune five people per instance. Although that's not exactly working as intended.

Still better then alcatraz, where Millhouse just stands around and completes the quest for everyone. You can easily attune the whole gulid in one empty instance. Gnomes. :/

And there is no aggro reset. After doing a shattered halls run every day for 2 weeks, we must have tried every possible way to min/max the aggro of everyone. An aggro reset theory is hollow, 2 aggro lists theory lacks too, and definitely its not a reverse either. Interchanging 2 random players is somewhat possible, but that doesnt give any dependable info; it's still random.

If it helps in your theories; when I tried soloing it till the second switch, to maximize threat on both heads, he just charged our second healer at the third switch and never came back to me, never; even invul pots on everyone didnt keep it on me, he went back to someone else after 6 secs.

For Kargath, regardless of your setup; tank all the ads, and kill him fast. The ads dont engage in combat until they step onto the platform, so you dont have to worry about healers building a ton of aggro when they finally get to you. He has close to 200k hp, but goes down fast enough.

How exactly do you use KTM to test an aggro wipe? Is there a certain line the addon uses to capture it, or something like that?

Believe it or not I did mine in a PUG, it was of course all very good people (warrior, hunter, priest, warlock [me], mage) but we didn't wipe once and just took it carefully and methodically. The second boss wasn't too hard for us, when I got aggro I took a invuln pot and when the mage got aggro he just kited around in a circle for 15 secs or so.

On the last boss, we pretty much ignored the adds - no fears as we didn't want to pull in assassins, instead nova, hunter pet, warr try to tank some. It is tough, I believe the mage died near the end. Healthstones, health pots, and just all out max DPS on the boss helps. Kargath dies pretty fast as long as you can push out heavy damage and stay alive.

Realistically I think the instance depends on a very, very good tank. If you have one you are golden. If your tank is undergeared you will have problems.

By the way I don't know if they fixed it, but if you have a shaman or warlock you can pretty much skip the 2nd and 3d boss. Just run right past Korgath into the area with the executioner (your whole group), go behind a bit, everyone die, then rez up and kill the quest guy. Its pretty dumb and I would imagine they have fixed it by now, but in case some of your groups are having serious trouble.

Its kind of like the entire I-did-strat/lbrs/etc-in-a-raid bugs, people who are playing now have a big advantage in keying over people months from now who will not be able to cheese stuff like Milli in arca or Shat Halls.

One other instance of a mob having an aggro swap mechanic very clearly defined would be the two shamblers before Thaddius. On the tank throw, the threat values of Mob A's highest threat dude and Mob B's highest threat dude are swapped on both mobs threat tables (have quite a bit of factual evidence, won't go into it unless someone wants to discuss it since it doesn't really pertain to this thread)

I'm not saying that's what happens with O'mrogg, but the functionality for that kind of mob behavior already exists. Except that now it could be rigged for highest-swapped-with-random instead of highest-swapped-with-fixed.

I don't see what the huge commotion is about, we did it quite easily. The only part annoys me is Om'rogg and the fact that you as a healer or tank probably need to do it multiple times. That you are actually able to 'leech' it makes it better though. Just form a daily group of the best possible setup, have 20 minutes to spare and get 5 people who need the quest in.