This is a bit delayed as I was not in for the first kill of this boss last week due to extenuating circumstances but having come in for it this week I felt compelled to write a little bit about this boss. The difficult thing is having not been present for the night they worked on him for the first time I never truly grasped the degree of difficulty for each slime combination and only really have a “feel” for the encounter which I found to be fairly easy and if anything is more a test of your DPS strength in meeting the berserk timer. There are no phases so I will break down what we used comp wise and how we spread out responsibilities. Hagara may be a little too easy for a primer but I will try to write one up on her shortly as well as Ultraxion.
Heroic Yor’sahj Primer
Tanks (2) – 1 protection paladin, 1 feral druid
Healers (6) – 1 restoration druid, 2 restoration shamans, 1 holy paladin, 1 discipline priest, 1 holy priest
Damage dealers (17) – even mix of ranged/melee. No balance druids present
The only time a healing assignment is ever really needed on this fight is whenever the purple ooze is present. At that point each healer was assigned one group of 5 players to be responsible for and one mastery focused restoration shaman was tasked with watching the tanks. No one was allowed to cross heal groups and healers were to be mindful of the Deep Corruption stacks present on their charges. I was responsible for group 2, though the specifics are largely irrelevant, and found no difficulty watching them during any purple phase.
We began the fight by grouping up on the edge of the pool of water directly in front of the green ooze starting location as that was our preferred ooze to kill. There are strats that suggest yellow ooze as a priority over the green with some exceptions but we found, given the strength of our healing, that prioritizing the green was more beneficial to our success. Our kill order was green ooze at all times, except when it wasn’t present and there was purple and yellow. In that case we opted to kill yellow. Killing the oozes themselves should not be an issue however if it absolutely became one for any particular ooze spawn the rogue (or rogues) on the boss could be called on to offer assistance. If absolutely need be tanks could come add some DPS though they generally spent their time off the boss helping on mana voids when applicable.
Blue Ooze/Mana Void:
The blue ooze’s mana void is handled slightly different in heroic mode. Once the first blue ooze makes contact with the boss initiating the mana drain the void is not killed during that ooze phase. Instead healers are reliant on mana regeneration cooldowns via mana tide, hymn if required, and their own innate abilities. For druids this means lining up power torrent, activating synapse springs if you have them (I happen to), and using innervate. You should generally be in pretty solid shape though worst case scenario if you find yourself in need of a little bit more mana a potion isn’t a bad idea to pop on this first drain. The mana void itself is kept at sub 30% HP until the next time a blue ooze makes contact with the boss. When that happens, and a second mana void spawns draining the raid’s mana the first void is then killed restoring everything that was taken initially from the raid. Bear in mind that the second void did not steal that much mana and when it is popped sometime later in the fight you will not return to full. The restores from these mana voids is generally enough to sustain you throughout the fight provide you make smart spell choices.
The moment of panic that may set in is during those few seconds after the mana drain but before the DPS manage to finish off the remaining life of the weakened mana void. Ideally you’d like to avoid using your massive raid cooldowns but there will come times where the mana void to be killed is just a little too high and going that long without any preventative measure will prove fatal. Do not hesitate to call for spirit link, aura mastery, or power word barrier. If the purple slime is not active and you have a divine hymn or tranquility free for use then those will help as well.
The purple ooze clearly adds a wrinkle to your game plan with the stacking debuff Deep Corruption. Some people may be less familiar with it as is the kill priority in the normal mode version of this boss. Given the deadly interactions of the other slimes we never chose to kill this slime and opted to heal through it as required.
Deep Corruption works as follows: every player gains the main Deep Corruption debuff with a timer duration of roughly 50 to 60% of the slime phases duration. While that debuff is active any heal (with some critical exceptions) will place a stack of a separate buff called…Deep Corruption. If that stack reaches 5 the player explodes dealing massive damage to the raid. Given the severity of these phases a single player explosion is generally going to be a wipe. The main Deep Corruption debuff eventually wears as well as the stacks but it is then immediately reapplied. This means all players will drop their stacks once roughly halfway through that slime phase. The second debuff duration wears off while the next set of slimes are making their way to yor’sahj. This is generally irrelevant unless you have active Black Ooze adds still up in which case healers will need to follow the raid and continue to heal them carefully.
What I did for this debuff was attempt to sneak in anything that I could at the start to improve my performance but often times little damage came to my group before my HoT’s expired. Just before the purple slime made contact with the boss I placed rejuvenation on each member of my group and refreshed lifebloom on the main tank. What this allowed me to do, should there be enough damage to warrant it, is swiftmend myself to drop effloressence and then barkskin to make sure that stack of deep corruption from a weaker heal didn’t cause an issue.
Heals that cause deep corruption stacks: Lifebloom, Rejuvenation, Nourish, Regrowth, Healing touch, Swiftmend, Tranquility (raid wiper)
Heals that do not cause deep corruption: Effloressence, Lifebloom bloom
(here is where I admit my knowledge is a little shaky, I’m more winging it on this section to be completely honest)
Black, Blue, Purple, (Green or Yellow, killed) – Arguably the tamest of the slime combinations. You’ll have only one set of Black Ooze adds and no active raid damage slimes up. This is an optional candidate for lust if your raid has the mana to carry through.
Black, Blue, Red, (Green, killed) – I believe we use Time warp/Blood Lust here as there is no purple to hamper healers usage of haste and only a single set of black ooze adds which increases boss uptime while buffed. It also helps get the mana void out of the way quicker especially if it is a little higher on HP. If there is a delay in getting the mana void killed before the raid damage starts getting high spirit link totem can be used to stabilize tanks and low players before mana is returned.
Black, Red, Yellow, (Green, killed) – Highest raid damage combination. We string together raid cooldowns during this combination using at least two each time it comes up. Power Word: Barrier is always our first choice and it is followed by a raid wide healing ability such as tranquility or divine hymn. Aura mastery and Spirit link totem if absolutely required can fill in if you have bad luck RNG wise with slime combinations.
Black, Purple, Red, (Yellow, killed) – Heavy raid damage occurs in this combination though the fact only one set of black ooze adds spawns is a godsend making life a lot easier. This is a great opportunity to use spirit link totem or, if your raid comb allows it, any non-rotation damage prevention cooldowns. Tank 4 piece cooldowns are fairly useful here as well as black/red/yellow.
Blue, Purple, Yellow, (Green, killed) – Moderate raid damage slime combination. Provided that mana is returned to the healers in a timely manner there shouldn’t be any difficulty in lasting through this phase’s AoE damage. Just plug away on your group as they take the shadow hits and you should be fine.
From a druid’s perspective we have different modes of healing dependent on what slime combinations are active. If purple is up you will play a bit closer to the vest and heal almost exclusively with Healing Touch (you will use Regrowth when applicable if it saves someone’s life or the debuff is about to reset giving you a HoT to use swiftmend with). Whenever purple isn’t up we go into full AoE healing mode using our standard arsenal of spells as we see fit. The only thing you need to keep in mind is managing your mana and scaling the degree to which you push yourself healing wise based on the difficulty of the combination at hand. Black/Red/Yellow for example is the deadliest and will require you to push yourself noticeably harder and consume a proportionately larger portion of your mana bar.
First, don’t troll me too hard if I misquoted when to use some abilities. I’m more pulling from memory as my guide here is primarily to discuss what I saw from a druid’s point of view. As we don’t have any major prevention cooldowns or tank abilities it really just boils down to how the raid handles the ooze phases, how efficiently the blue and black ooze abilities are handled, and how well you can keep up with the damage with Deep Corruption active. We may not bring any unique major cooldowns to the table for this fight, but we are far from a liability in my mind. Focus hard on keeping your group up and let your HoT flag fly when unrestricted raid healing is required!
Good luck and happy hunting.