How To Raid Immerseus on Flex

Immerseus is a raid boss that does more up-downs than a football player in spring training.  He seems relatively straight-forward, and pretty weak, until you take his health down to zero and realize the fight is not over.  Instead of dying, this boss splits into little blobs, before reforming again later. This pattern repeats itself several times before the boss fight is over and if you fought him in a looking for raid group, you probably just mindlessly killed him until he doesn't pop back up again.  However, there is a method to this madness, and I will try to show you what it is.

The Boss:  Immerseus is deceiving because his health is not where you think it is. Instead, there's a small purple bar at the bottom of his character portrait called his "corruption" (see right picture). That bar represents his true "health" in a sense.  As it goes down, you'll notice the boss keeps popping back up with less health. So, the true goal of this fight is reduce that corruption bar to zero.  This is done when he splits into blobs. For every Sha Puddle that is killed, and every Contaminated Puddle that is healed to full, this boss will lose one corruption point.

Note:  This boss is always the strongest at the beginning of the fight. Since he pops up with less and less health every time, its a good idea to use soft cool downs (anything with more than a minute cool down) and bloodlust/time warp at the beginning of the fight.

Layout:  The room is split into 7 "pie pieces", surrounding the boss, with one piece that is larger than the others. The water running between each pie piece is harmless, but the water where the boss is standing is quite deadly

Positioning:  I would recommend putting the tanks near each other. Some like to have the tanks in the front of the room, on separate small pie pieces, others like to put them in the back of the room, on the large pie piece, but on opposite ends of it. So long as the tanks know what they're doing, it doesn't matter where they tank. Putting them next to each other just simplifies things. There should be a healer flanking each tank in this fight. The rest of the raid will position themselves throughout the room so that they are both (1) spread out and (2) in range of a healer. However, no one should be on the same pie piece as a tank.

Abilities:  There are mainly three things to watch out for on this fight

• Sha Bolt - he will hit everyone in a flex raid for a minor amount of damage, but then a sha pool will form underneath your feet.  All you have to do is shuffle off to the side to avoid the damage it will do. In flex, you will be targeted by this black pool every time he casts it, so be ready to shuffle your feet.

• Swirl - the boss will do his best impersonation of a water sprinkler, he will damage and knock back anyone caught in the downpour.  This ability will move clockwise and cover about half of the room. The boss faces where he is going to cast it, so it is possible move out the initial danger zone before it hurts.  Otherwise, moving to the back wall or just simply outrunning it by moving clockwise can help you avoid damage, though I wouldn't recommend the healers and tanks do this.  While this is going on, there will also be tornadoes of water that will move around, these too must be dodged.

• Split - the boss will split into numerous blobs that will land near the outer walls.  The DPS must kill the Sha Puddles and the healers must heal the Contaminated Puddles before they reach the center.

• Additionally, this boss does Corrosive Blast, which is an ability that should only hit the tanks (unless someone is standing right next to them).  This does considerable damage and gives them a debuff that will increase the shadow damage they take.

From a Tank's Perspective:
The key to this fight is taunting off whenever one tank gets hit with Corrosive Blast.  As soon as you see the other tank get hit, taunt the boss and then make sure to keep him until he hits you with Corrosive Blast. There have been times when the boss has gone into his water sprinkler phase and then targeted the wrong tank afterwards, so just remember to re-taunt if you lose aggro.  The only other concerns are the sha pools you have to shuffle off of occasionally.

From a Healer's Perspective:
This fight can be a little chaotic sometimes, especially if the DPS likes to stand in sha pools or if they have low health.  Healing this fight is about ignoring the stuff you have to ignore and paying attention to what's important.

If you're tank-healing, look for the Corrosive Blast, because that is when the your tank will take the most damage, so any spell that can reduce damage will be a great asset if you cast it on the tank right before the Corrosive Blast.  DPS should be a secondary concern during the normal parts of the fight.  The occasional heal or heal over time spell should be enough to keep them good.

When the boss shifts into Swirl, the priorities flip.  The tank becomes less important while the boss is doing this, because the boss will no longer be hitting a tank, he'll be dousing the raid group with damage that will hardly hurt a tank but may kill a DPS or a healer if they're already low enough.  So, mostly ignore the tank and focus on keeping yourself and the DPS alive while the boss is doing this.

When the boss finally Splits, you find the Contaminated Puddles (the greenish-blue looking ones) and heal them up before they reach the middle.  Note that every heal you cast on them slows them down.  So, if you position yourself, you can cast your quickest heals on multiple puddles, and then use your longer, more effective, heals to top them off.  It is also a good idea to stand near the puddles when you top them off because they will give you mana and increase your healing.  As the fight goes on, there will be more Contaminated Puddles, so it will become increasingly important that the healers heal these up.

The most damage that the raid will take on this fight occurs when the Contaminated Puddles begin to reach the center.  So, save your biggest heals for right after that.

From a DPS's Perspective:
This boss seems the same as the looking for raid version, but he allows you a lot less time to stand in one place.  In flex, he will target you with sha pools every time he casts Sha Bolt.  So, this fight is a test to see how effective you can be when you can only stand and cast a couple spells before having to move again. Naturally, melee DPS and mobile ranged DPS have a much easier time with this fight than, say, a mage.

Your job in this fight is pretty straight-forward, kill the boss until he Splits, then kill the Sha Puddles he spawns.  Use you soft cool downs early in the fight, because he won't be up long enough for them to be effective in the later parts of the fight

However, if you want to contribute to the group and be less of a burden, its very important you avoid needless damage.  Don't stand in the sha pools and avoid the Swirl by moving to the back wall or, more preferably, running clockwise until it stops.  Just remember to run back to your position afterwards.

Remember, that when the boss splits and the puddles he spawns begin to reach the center, that's when you will probably take the most damage, so anything that can either reduce damage or heal yourself is something you should use.

I hope this helped.  Please contact me with any questions, comments, or suggestions.