This is a very elaborate 3 phase fight. For phases one and three you will alternate focusing down a huge pool of health and dealing with mechanics. For phase 2 you’ll have to alternate grouped movement and nuking down priority targets. Windwalker does very well here.
For phase one, your priority is to get bloods down after each breath.
Serenity is the better option for single target damage on Helya and few targets cleave on priority targets like Night Watch Mariner, tentacles and Grimelord. However, Storm, Earth, and Fire has a smoother learning curve, helps to deal with bloods after breaths if you struggle on it. If you feel very uncomfortable going Serenity on this fight, you might want to consider Storm, Earth, and Fire. Disregard the damage it deals to decaying minions phase two to judge its viability. This is not very relevant to killing the boss.
The best way to survive here is to have good knowledge of what’s going on and what will happen soon at all time. Being ready for Orb of Corruption fixates, being aware of Taint of the Sea debuffs, all things which will help you out immensely.
Diffuse Magic will act as a self dispel on a 2 minutes cooldown here. Be careful when using it as it will drop the Taint of the Sea void zone wherever you are. You don’t wanna deny positioning to your teammates.
If you’re not using Transcendence much, you can use it on top of the two upper platforms. This will allow you to bait Orb of Corruption there, avoid Fury of the Maw and jump back down or several other neat positioning tricks.
In the future these might seem off because available DPS varied a lot, so for the record this was last updated december 9th, 2016.
All the positioning tips are way more relevant here. Be very careful of where you are with Taint of the Sea and when you use Diffuse Magic. Dropping the debuff at the wrong place can mess up a lot of things.
Move ahead of schedule when the melee orbs are spawning, 4.5M ticks are quick to kill you.
The Bilewater Breath spawns orbs that are way deadlier than on lower difficulties. Luckily, we can easily jump from one target to another, gathering stacks of Spinning Crane Kick and cleaving 2 bloods and the boss with Fists of Fury or Strike of the Windlord. Always take advantage of the boss’s big hitbox.
It is stronger than ever here to have Transcendence ready to jump to the towers and bait Orb of Corruption out since these are the most important ability on mythic. Do so with care though and be ready to Diffuse Magic if things go wrong.
Phase 1 breakdown::
You want to learn how to survive this phase first. Once you learn the moves, it will be easier for you to see when you have long periods of time where you can safely dps/AoE slimes. Right now, this phase lasts around 3 – 3:30 minutes.
Make sure Transcendence is allways in a safe spot and you know where. I usually drop it next to the right pillar early on in the encounter and refresh it whenever I port back to it.
Boss will alternate orbs targeting ranged dps (odd orb waves) where you can be in a safe spot and melee dps, where you’ll need to be at the right position. You also know for sure that you cannot be targeted by two consecutive waves of melee orbs. This means if you just got targeted by orb, you run out with other targets, transcendance back to the boss with 1.5 seconds left on orb roughly and are safe from orbs for the next 3 waves.
Third breath happens around 1:40 into the fight, meaning you can probably use serenity on this wave to gain huge damage on the boss/slimes. You will likely not lose a relevant cast of serenity there since next one comes up around transition anyways.
Make sure you help out your healer by making the most out of your mobility to get into mass dispell markers or use transcendance to minimize the personal dispells you’ll need for taint of the sea.
Phase 2 breakdown:
The first thing to do when getting to your tower is setting up transcendance, preferably towards the middle of the boss room. Use serenity on two targets (Mistwatcher/grasping tentacle) to burst these two down then cleave tentacle and either grimewalker or Mariner. Careful, grimewalker casts the ground AoE right after the tank Anchor. Once these are dead, follow your guild’s tactics to kill decaying minions and grasping tentacles. Touch of death probably comes up around here, Mistwatcher probably dies too quickly for it, grasping tentacles don’t. If you are using legendary gloves, save it for second grasping + mistwatcher.
Once the decaying minions are dead, you can help finish the tentacles and instantly use Transcendence back to the tower, gaining high uptime. Cleave down the high priority targets again. Serenity will come up late here, but note that if you use it it will be up in time for first phase 3 mariner anyways. It can make a big difference in finishing Grasping tentacle + add.
Finish this phase with your group. If decaying minion dps is an issue, transfer the power stacked up can help getting a sick Fists of Fury for burst AoE.
Phase 3 breakdown:
This phase will ask for very good damage and survivability.
It is highly advised to really learn before hand the whole positioning rotation your guild intends to do, and if it’s based on some guild’s tactics, watch their videos.
If you are using Hidden Master’s Forbidde Touch, make sure to line up your few TODs with mariners. However, you probably won’t be able to line up that many, so you might want to use touch of death early on single target since first mariners are way easier to cleanly kill than the later ones.
Use defensives (touch of karma, diffuse magic) smartly. Spot at what point your ranged are far away for orbs targeting purposes (on the tower, in the back of the room, etc) because that’s when you’ll be most vulnerable.
Use your favorite spell, Transcendence, to port above waves. When fury of the maw is cast, you can double roll backwards provided you don’t run into orbs or others, then transcendance back at the right time to avoid most knockback/damage.
Make smart use of chi wave and crackling jade lightning to keep hitcombo up when you are out of range of the boss.
Don’t hesitate to use leg sweep to stun minions in the right spot for decay to spawn. You’ll quickly learn when fury of the maw hits and cleans, aka when it’s safe to drop stuff everywhere.
Be careful, fists of fury / strike of the windlord / serenity / touch of deaths are your tools when a mariner needs crazy damage. You can’t just press Fists of Fury on cooldown and expect a few blackout kicks to be relevant damage there.
Decaying Minions on phase 2 have this neat particularity that people are not supposed to kill them until the raid is ready to deal with decay properly. This is a rare case where Windwalkers can stack up Spinning Crane Kick to very high amounts before AoE even start, giving us an edge. If you’re using Whirling Dragon Punch, don’t hesitate to pop Storm, Earth, and Fire a bit early and go Tiger Palm -> Blackout Kick to stack up chi and get 15-20 stacks. Even if Decaying Minions die instantly, using these 15 stacks will destroy Grasping Tentacles very fast.
This is the easiest fight to soak Touch of Karma damage as it is usually very easy to walk into water. You’ll take 500k damage per second on Heroic, closer to 1 million damage per second on Mythic. If using Cinidaria, the Symbiote, this will allow you to max out this scary legendary. I’d advise doing so intelligently.