6.2 Hellfire Citadel - Mythic Halls of Blood

This page is to be a brief summary on the second wing of mythic boss fights of Hellfire Citadel, written from the perspective of a hunter. The purpose of this is to act as a documented archive of our kills and to potentially aid any others currently working on the boss who're looking for resources and happen to come across the page.
 Gorefiend is widely considered the raid block and guild killer of this tier, so I will try to provide extra information for the fight.

Fourth boss is HELLFIRE HIGH COUNCIL

First kill was July 9, 2015 - world 125, US 28

Hellfire High Council has been a headache for many guilds. Blizzard has constantly been changing the timing and mechanics for Dia, slightly modifying the way the fight is done each and every week. Our first video is not useful any more, so I will be including a video from August 11th, which will be different as of August 14th (slightly).

There are different strategies here, but the most popular is to burn Bloodboil first. This is also how we do the fight, which is why it will be written from that perspective.  Barrage can be angled to hit all three bosses and should be used on cooldown, except in the case of saving it to line up for the Blademaster's whirlwind phases. Moving in and out for Bloodboil stacks is easy - count to 3, rotate, repeat. You can see the cast flying towards raid members if you don't have a weakaura that counts the stacks.

Deterrence is a god send on this fight. Whenever you get mark, you may have it dispelled - or you may have to run the reap out of the raid. If your mark is timed so that you have to run it out, pop deterrence on the reap alert and go stand on a prior cast reap void zone. Then walk back to the raid, completely unscathed and without having hurt anybody else. The biggest issue people face are folks dying with reap, so the mark hops to a new set of people who also then get reaped.

Finally, ghost tails hurt. If you have to dodge a ghost, make sure you are dodging long enough to avoid being hit by the ghost.
Here are all the weakauras for Hellfire High Council, including an airhorn for Reap being cast, bloodboil stacks, Fel Enrage being fixated on you (the damage buff), and the various stages of mark (red marks hurt and you'll need extra healing / exhilaration):
http://pastebin.com/iN8B5VSS

Our first kill:

August 11th kill:

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Fifth boss is KILROGG DEADEYE

First kill was July 12, 2015 - world 142, US 27

Kilrogg is a simple fight that can quickly get out of hand if adds aren't handled correctly by the team upstairs, or the downstairs team is unable to do their job - or fail to clear out adds when they come back upstairs. Hunters should almost never be going downstairs, so you won't get a perspective there. 

Instead, hunters should focus on having the highest uptime and damage done on Bloods/Fel Bloods by pre-emptively filling their focus bar to dump on them during impales. Similarly, a hunter should prioritize ensuring none of the little orcs get to the alter and to snipe on Terrors otherwise. In other words, Bloods > small orcs > large terrors. 

You don't have to run around a lot for Death Throes. Most of the time all you have to do is strafe left or right two or three steps, then strafe back ... Similar to the tempest on Velhari. 

Terrors are the main add that can get out of hand if melee are not able to keep up. All you really need on the bloods is one or two hunters with one or two warlocks, so put as much pressure on them as needed and direct all other pressure into the terrors. Of course, any small orc that's going to slip by the casters needs to be dealt with first. Similarly, when terrors are being moved out sometimes the melee can't interrupt them and it will fall to a ranged (like a hunter) to interrupt instead. 

Apparently I did not highlight our first Kilrogg kill. Instead I have highlighted our most recent kill, which was unfortunately muted by Twitch. However, it is a very good example of how things can go very wrong, very quickly if adds are messed up. It's also a good example of how we handled messing up our adds, starting from getting three fel bloods to getting our tank mind controlled by extra terrors. 

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Sixth boss is GOREFIEND

First kill was July 22, 2015 - world 126, US 24

Gorefiend is the road block for most guilds this run. To do the fight you're aiming at killing Gorefiend during or shortly after the third feast. Getting to this point involves a secondary phase: we can split this up by saying there's a phase 1, add phase, and a phase 2, feast phase. During phase 1 add phase any damage you do to Gorefiend is the equivalent of a tickle - therefore, don't waste your time trying to optimize your Gorefiend damage at the expense of cleaving other mobs or AoE. In fact, just ignore Chimaera unless you know where it will be cleaving (IE, once you're on the Spirit upstairs).

You will likely have people assigned to breaking out Corrupted Souls, and it will not be a hunter. However, a hunter can help on a tanks Corrupted Soul with one or two Careful Aim Aimed Shots. Hunters can also snipe kill shots on Corrupted Souls under 5s left on their duration. 

During add phase you should sit at mostly full focus, spamming nothing but your focus builder on Gorefiend while you wait for adds to show up. Alternatively, you will get Shadows of Death, upon which you'll stack at your stack spot and go downstairs - still with a full focus bar. Your priority upstairs should be Constructs at all times. Windwalk will immune the Essences. Hunters are ideal for killing constructs, and if your basement team messes up, it's your responsibility to make up for it. If you DO get Shadows of Death, keep this in mind:  there are three cycles of SoD. The first one is easy, the second two the Shadows of Death team must take due care. When you go down there will likely be high health constructs about to exit. You must handle them with knock backs or stuns. Thus, make sure you're prepared with a glyphed explosive trap or a binding shot. Always aim to get the most out of your knockback and stun. Otherwise wreck on Shadowy Constructs with Aimed Shot and Kill Shot. It is not a totally bad idea to throw some of your cooldowns when you're down here too, if necessary. Your raid feast damage is likely good enough. I did this on cycle 3 of add phase 3, before the final feast.

Gorefiend is almost entirely an add management fight. The Shadows of Death basement is essentially the same damage boost as a Gorefiend Feast. The adds have less health downstairs, then gain substantially more when upstairs: if you can do damage to them downstairs, or outright kill them, it's like doing x2 the damage to an upstairs construct.   Here's the main thing though: the Shadows of Death team is not enough to handle the basement phase. 

You must sacrifice a player to go down and deal with the Enraged Spirit. The two Shadows of Death targets must focus on their job killing constructs.  It's also a good idea to sacrifice an additional player just to use all your firepower. We generally did this between Shadows of Death 2 and 3. To sacrifice, simply hop in the pool with Gorefiend. Any Doom Wells cast on you will show up under you, but it can be avoided if you're off to the side. Another player will have to watch your digest timer.

If you're the sacrifice going down to handle the Enraged Spirit with the tank, use down time to kill Constructs. Your goal for the Enraged Spirit is to whittle it until it's almost at 70%, then burst it as hard as you can so that it gets as low as possible before casting its damage reduction and running out of the stomach. If you're sacrificing additional players after this Shadows of Death cycle, you should focus entirely on constructs. 

Regarding talents... You don't need barrage. You won't get too many opportunities to use it. Glaive toss can be useful downstairs, as can Power Shot. I like to keep barrage since it can be a life saver upstairs if things start getting hectic - all it requires is making sure you aim it properly. The best time to get use out of it is after Shadows of Death 3, because all Corrupted Souls should be out and the raid should be preparing for the Feast. Wipe out all remaining mobs. 

To make this more clear, the phase 1 add cycles look like this: 

[SoD DPS 1 , 2 DPS

Extra Spirit DPS, 1

Tank

Healers

SoD DPS 2, 2 DPS]

[SoD DPS 3, 2 DPS

Healers

Extra Spirit DPS, 1

Tank, Extra Construct DPS, 1 

SoD DPS 4, 2 DPS]

Feast

Once you're able to get past the first 2 minutes of the fight (one add phase), the rest is simply repeating the trick. As you complete each add phase, the Doom Well drops become more and more dangerous and the raid must stick more and more towards the middle. Emphasize the cast if you have to, and make sure you are never near anyone dropping their Doom Well. Similarly, never stand next to a Construct who is spawning upstairs. That's just asking for it to fixate on you and immediately blow up.

Here are some weakauras: http://pastebin.com/jUTvD1xM