Source: Dulfy (and thanks to all the Oops'lings who helped create the class-guides and changes to the boss-guide).
GORSEVAL THE MULTIFARIOUS GUIDE
Gearing and Preparation
Unlike Vale Guardian, Gorseval is a pretty big DPS check so you will definitely want to have full ascended if possible. On this fight it is possible to have sub 1% wipes so having every bit of DPS will definitely help.
You need to figure out pre-fight who is taking care of which Charged Soul. You need 3 players who can hold down 3 of the Charged Souls with cripple/chill and immobilize while rest of the raid form a zerg team that kill each of the Charged Souls one by one. Additionally, you need to figure out which Tempest is clearing the orbs and which one is acting as a backup.
You must have Updraft Usage mastery for this fight. Additionally, defeating the Vale Guardian will unlock the Rift Traveler mastery which you also need for a quicker access to this boss for repairs. If you don’t have this Rift Traveler mastery, you can /gg or /qq and you will spawn near Gorse.
Gorseval has 21.6 millon HP and an enrage timer of 7 minutes. There are 3 general phases.
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Phase 1 starts from the beginning of the fight until the first invul phase at 66%. Do not attack Gorseval until everyone has landed on the platform as the updraft that carries you to the fight area disappears as soon as you attack him. This pattern in this phase is basically Swipe/Smash –> Ground Pound –> Spirits –> World Eater –> Swipe/Smash –> Ground Pound –> (Spirits) –> Invul/Charged Souls.
Updraft here is a bit tricky to use. To get maximum height, you must not press or hold down your W key while inside the updraft or you won’t gain enough height to reach the platform. Press W to get inside the updraft and once you are inside, take your finger off the W key and gain height before pressing W key again.
There are only four updrafts for this fight, not counting the initial one that carry you to the fight platform which will disappear as soon as the fight starts. There will be phases in the fight where you need to use updrafts to get away from the fight platform and these specific updrafts will disappear once your team has used them. You must minimize your updraft usage as you have a limited number of them and using them is a DPS loss that will get you in trouble with the tight enrage timer. The four updrafts are located in the 4 corners of the platform, and we usually label them using the cardinal directions (NW, NE, SW, SE).
Another tactic is to use "no updraft". For this tactic you need to have good DPS in your team, and you want to SLOWLY break the CC-bar. By doing this, you gain some extra DPS-time on Gorse before he do his "World-Eater" attack.
Swipe and Smash
Gorseval has two basic attacks, a swipe and a smash. The basic pattern for them is swipe-smash-swipe-swipe-smash. He will usually open up with a swipe but sometime with a smash as well. Tank need to turn Gorseval to avoid him from cleaving the raid. The smash is the one you need to watch out for as Gorseval will raise one of his arms in the air and then plunge it into the ground. If you do not dodge it or have Aegis to block it you will be knocked down and lose a few seconds of DPS.
Ground Pound is a special attack Gorseval will perform that require Crowd Control (CC's) skills to break his bar. He will do this attack typically twice in this phase. Right before he starts this attack, he will run back to the center and gain a breakbar. The center of the room will be safe for the first two patterns while rest of the area is filled with a black goo except a ring at the outer edge. If you stand inside this black goo when it explodes, you will be dealt massive damage and receive 25 stacks of vulnerability. If you are downed while inside this black goo, you will die when it explodes so it is important to rez downed players ASAP. If you do not breakbar this fast enough, the entire room will be filled with this black goo and it is essentially a raid wipe.
Typically you want to remove this breakbar as fast as you can as the boss gains permanent retaliation (713 damage per hit) while this breakbar is active that will do some serious damage to classes like Tempests (Rebound here may help). Some burst healing might be needed here so druids should have their Celestial Avatar form ready. In organized groups we sometime delay the second Ground Pound breakbar so we push him into the next phase and avoid spirit spawns but this may not be necessary if you have good DPS. Revenants should be doing majority of the breakbar here and Tempests can drop Icebows here for Revenants to use since switching to staff is generally a DPS loss.
Four spirit adds spawns usually right after the Ground Pound. They can be either Enraged Spirit or Angered Spirit. Angry Spirits will try to cripple you while Enraged Spirits have a strippable boon that makes them immune to physical damage and will try kick people around. It is very important to get the spirits under control as they can gang up on the Tempests or kick players constantly (even off the platform if the Spectral Wall is down). For the first set of spirit adds, we typically group them up and pull them next to the boss for cleaving. Mesmer Focus #4 or Revenant Axe 5 or Guardian Greatsword skill 5 can be used to group them together.
If you push Gorseval into the invul stage fast enough (i.e. 66%), you can avoid the second set of spirits spawns. This is why we sometime delay the breakbar phase on the second Ground Pound so we have more time to DPS and push the boss over. If any of the spirits remain alive on the platform during the World Eater attack, Gorseval will consume them and gain a stacking damage buff of 10% per spirit. If the spirits are badly managed you may see 4-5 stacks of this buff on Gorseval and at this point the fight can get pretty difficult due to the damage increase.
World Eater/Spectral Wall
World Eater is a special roomwide attack by Gorseval that will kill anyone left standing in the platform once he finishes channeling the attack. The entire fight platform lits up and an inner circle expands from the middle and reaches the outer edge. There will be a massive explosion a few seconds later and anyone on the platform is instantly killed.
To counter this attack you will need to drag Gorseval to a Spectral Wall next to one of the four updrafts so you can cleave/AoE Gorseval and the Spectral Wall at the same time without wasting DPS on the wall alone. Remember you can only use each updrafts once.
The Spectral Wall has a huge hitbox so if you position yourself correctly you will be able to hit both at the same time. Tempest Meteor Shower/Lava Font will hit both and melee can cleave in a direction perpendicular to the boss and the wall. Once the wall is broken, DPS Groseval until the inner ring of World Eater almost reaches the outer and then jump off to glide on the updraft. Do not jump off early as doing so is a DPS loss. Healers need to make sure that everyone is topped off while gliding as players can get attack.
Glider malfunction is one of the common deaths on Gorseval. To prevent this there are a couple tricks. You need to disable autoattack as the aftercast from abilities can cause your glider to not deploy correctly. You want to hold down your spacebar after you do the leap so you deploy your glider immediately. If you see your glider not deploy, release your spacebar and attempt to deploy again. Once your team has used an updraft for this phase, it will disappear for the reminder of the fight.
The Charged Souls phase happens exactly at 66%. Four Charged Souls will spawn in the four corners of the room roughly in the same locations as the updrafts. They will attempt to run to Gorseval and if they reach Gorseval, who is now invul, Gorseval will come back to life and cast World Eater, which is essentially a wipe. The Charged Souls also pulse AoE weakness around them so you should always max melee them if possible.
Some raid teams do this differently but most raids pick 3 players to immobilizing/cripple/chill 3 of the Charged Souls while rest of the zerg start at the remaining one, and go around clockwise to kill them. Only Cripple/Immobilize/Chill works here and other crowd controls such as a knockback/daze etc do not work.
Phase 2 occurs from 66% to 33%. Phase 1 mechanics still remain unchanged but there is also a new mechanic being added.
Spectral Darkness are these orbs that spawn randomly throughout the room during the entire phase. They are harmless initially but they will expand out to an AoE if not killed quickly. Anyone that touches this AoE will get a 10 stack debuff that reduces their outgoing damage and increases their incoming damage by 10%. This debuff also ticks for 2k per tick. To remove this debuff you must run to the golden droplets that spawn after you kill an orb. Each golden droplet will remove 5 stacks of this debuff. You only want the ranged to clear these orbs as melee clearing them risks having them stand inside the AoE and eating the debuff.
Staff Tempests really shine at orb clearing duty so if you are using Tempests one should have the main orb clearing duty while the others act as backup. A single Lava Font with some autoattack will kill an orb. You want to clear as little orbs as possible to maintain DPS uptime on Gorseval. You only need to clear orbs that are in the path to the next Spectral Wall for the next World Breaker and orbs that are in the way of the Charged Souls.
The next Charged Souls that occurs at 33% will be a little interesting due to the orb placement so it is important to clear these orbs as soon as possible or otherwise you will have trouble with the Charged Souls getting to Gorseval too fast.
Phase 3 is the last 33% and has all the mechanics with Phase 1 and 2 along with new and modified mechanics.
Ghostly Traps (Eggs)
Ghostly Traps are orange circles that appear under every player on a semi regular basis (every 20-25 seconds) past 33%. You will see the message Ghostly Traps materialize at your feet. These orange circles will appear seconds later usually after a Smash. It is very important that you do not get egged here by the Ghostly Traps. You have time to dodge out or strafe out (back peddle is usually too slow). If you fail to do so, you will get enclosed in eggs and will need to spam the special action button (- button by default) or have other players break you out. If you dodge into an orange circle (even if you are mid-dodge), you will still get encased and blocks/evade does not work.
Getting encased in eggs is a huge raidwide DPS loss and it is super important to not get encased. Other players can help break you out of the egg by dps'ing.
Ground Pound Pattern Change
Beware that the pattern for Ground Pound changes past 33%. You won’t see this change with the first Ground Pound past 33% but the subsequent ones will have this new pattern. The middle area is no longer safe for the first two pattern change so you will need to stay away from the middle and then dodge into the middle on the third pattern change. The first three patterns are shown below in sequence.
- and ofc, some Lulle Art
Oopsy Videos from Gorse