Green Board present's Valkyrria's 10M Guide to Immerseus Video was created by Mrsquishei https://www.youtube.com/user/MrSquishei?feature=watch These were meant for green board guild use.

1. VALK’S 10M GUIDE
TO
Immerseus will be the first boss you will
encounter in the Siege of Orgrimmar Raid.
This boss is a relatively simple 2 phase
encounter. Unlike most boss
fights, however, this fight is not over when the
bosses’ health reaches zero; it is over when
the bosses’ energy bar reaches 1.
2 Tanks
3 Healers
5 DPS Bloodlust should definitely be used at the beginning of the fight, as that is when you can get the most out of it.

2. Phase 1
For Phase 1, Immerseus will be stationary at the center of a circular room that has 6 lines of water dividing the circle into platforms 6
platforms, 2 large and 4 small. The 2 large platforms will be in front and behind the boss, and the 4 small will be split into 2 small platforms
on either side of the boss.
The tanks should stand in front of the boss but not next to each other, as Immerseus uses Corrosive Blast, a frontal cone shadow attack
which places a debuff on anyone hit which increases Shadow damage taken by 300% for 45 seconds. He will cast this ability every 30
seconds. A healer and a DPS should stand on a platform on both sides of the platform occupied by the tank. The remaining healer and
DPS should all stand on the large platform directly behind Immerseus.
Sha Bolt is cast every 10 seconds and hits every member of the raid. It deals shadow damage which can splash to anyone within 5 yards
of the player. It will also leave a small void zone under the player. To deal with this, a player should simply step to the left or the right and
continue DPSing. Ideally, this should be as close to the boss as possible.
Swirl is a big cone attack that shoots out a stream of water at the raid. While he casts this, Immerseus will rotate clockwise at an
extremely fast pace. To counter this, simply use movement increasing abilities or immunities. It is possible for a mage to blink through the
Swirl to the other side safely but is risky. While this is happening, some void zones will begin to move and knock players into the air if they
are hit.
During this phase, Immerseus will use two major abilities aside from the tank debuff.

3. Phase 2
Phase 2 will begin when Immerseus reaches 0%. At this point, he will submerge, becoming un-attackable. All void zones will head to the
center of the room, which is why we want to place them close to the boss. Two different kinds of adds will be flung from the center of the
room towards the wall, all over the room. The object of this Phase is to kill as many of these adds as possible to prevent them from
reaching the center. These adds are Immerseus’ energy. The less energy he gets back, the less health he has in Phase 1, the quicker
Phase 1 will go.
Sha Puddles must be DPSed down and can be stunned, rooted, and slowed.
Contaminated Puddles must be healed and will slow down the more they are healed. When they are fully healed, anyone within 12
yards will receive 75% increased healing for 15 seconds.
If any puddle reaches the center of the room, it will do a raid wide AOE that does a significant amount of damage. However, if a fully
purified puddle reaches the center, it will still do an AOE but do much less damage.
After all the stacks reach the center or after 30 seconds, Immerseus will reappear and begin Phase 1 again.

4. Summary
All in all, Immerseus is a loot piñata. It is
a very easy fight and should not cause
your raid any problems as long as you
are all awake.