This guide will assume you are familiar with the Heroic version of the fight and expand on how the fight changes in Mythic difficulty. If you are not familiar with this encounter, check out our heroic guide by clicking the button below.
The mythic version of G’huun introduces two new mechanics and has some changes to the mechanics of Power Matrix. The change to Power Matrix is quite involved. First, you are unable to use abilities while holding a Power Matrix. Second, once you pick up a Power Matrix, causes a Matrix Surge to chase after the holder of the Power Matrix which will kill anyone if they are hit by it. The third change is you need to dunk two Power Matrix‘s into the Reorigination Drive within 3 seconds of each other. This means as a raid you will need to dedicate multiple players to dunking both sides of Power Matrix‘s at the same time. The easiest way to go about this is to have a total of four warlocks use Demonic Gateways (2 on each side) to deliver the Power Matrix‘s to the Reorigination Drive as fast as possible without needing to clear the Amorphous Cysts that are on the upper level. There is one last change to orb running which involves the Amorphous Cysts new ability, Tendrils of Corruption. Tendrils of Corruption move between the Amorphous Cysts that root any player that touches them. If you move along the upper level with an emphasis on staying towards the arena, you should never be in the path of the Tendrils of Corruption.
On the arena floor, you will notice a few changes, the first of which resembles the Infested mythic+ affix. Whenever any add dies, whether it be any of the phase 1 adds or a Gibbering Horror in phase 2, multiple Spawns of G’huun will spawn from the corpse. These adds fixate on players and chase them until killed. If any of these spawns reach the target they are fixating, they will infest that target which applies Blood Host, a small damage over time that is a disease. When the disease is dispelled or expires, two Spawns of G’huun will spawn near the player that was just infested. The goal is to never get infested and slow and stun the Spawns of G’huun to avoid needing extra healing and damage throughout the encounter. The other new mechanic is Bursting Boils. Once G’huun leaves his cave (phase 2), he will periodically spawn three Bursting Boils around the room. These boils explode after 8 seconds hitting the closest two players to each boil. Being hit by a boil leaves a stack of Bursting Boil on the player which deals small damage over time for 30 seconds. If any player were to get two stacks of Bursting Boil, they are mind controlled and must be killed. If you are the closest person to two boils, you will gain two stacks, but you cannot get two stacks from one individual boil. Bursting Boils spawn around every 24 seconds, which makes you unable to soak back to back boils unless you pause the boss encounter by triggering a Reorigination Blast. Bursting Boils continue to spawn in the third phase.
Since the fight have multiple stacked phases, and the fight is generally 5 healed, it is best to double down on stacked healing by taking Downpour and Wellspring to excel when the raid is stacked and to allow other healers to pick up some of your slack when the raid is spread. You are going to want to use Unleash Life on Riptide on this boss as there is a ton of damage over time effects and Riptide can provide a lot of throughput during the moments when your raid is spread. For the 60 tier, any of the talents are good options, APT has a lot of value though since the last phase is a hard burn phase and you might have some raid members go into it with some stacks of Putrid Blood. It is better to let one of those members die inside of APT and remove their stacks rather than try to dedicate a ton of heals into them.
Notable Azerite Traits
Sprouting Spirits is amazing on G’huun due to the need for every healing cooldown your team has in the final phase. By taking Sprouting Spirits, you are able to use SLT as a throughput cooldown during Collapse and other stacked points (Reorigination Blasts) on the fight to supplement other healing cooldowns. Other than that, Swelling Stream is as always a great option for overall throughput.
Mythic Healing Tips
- Effectively rotate cooldowns through Reorigination Blasts, Mind Numbing Chatter casts from Gibbering Horrors and Collapse while budgeting to have a large majority of cooldowns up for the later parts of phase 3.
- Use Ghost Wolf before grabbing a Power Matrix.
- Take advantage of points where your raid is stacked and dump a lot of mana during these moments to increase overall longevity of your raid.
- DPS as much as possible in phase 3. Killing the boss faster means there is less of a chance of someone getting mind controlled from bad Bursting Boil spawns.