Our raid comp;
- Prot Warrior
- Blood Dk
- Holy Priest (me)
- Resto Druid
- Resto Shaman
- Fire Mage
- Elemental Shaman
- Balance Druid
- Assassination Rogue
- Feral Cat Druid
We had an average item level of 348 (I had 349).
Preparation
Like I mentioned, Maloriak is divided into two different portions. The first portion of the fight, or the first 75% of his health he'll go through various phases which have to be handled differently. There will also be adds. So the first portion of the fight is about dealing with fight mechanics. When he reaches 25% he'll go into a soft enrage, which isn't too difficult. Actually it's easier than the first part of the fight because there is way less things to think about. The trick is to down him before his real enrage which comes after 6 minutes. If you have enough damage this shouldn't be any problem and this fight will be cakewalk. We noticed that we had just about exactly the amount of damage needed and that made the last 25% a little trickier. Try to get about 100k total raid dps and this shouldn't be a problem.
100%-25%
During the first 75% of the fight, Maloriak will use different abilities. He'll either use a blue vial, a red vial or a green vial, and depending on which he'll use you'll have to react differently. He'll always start with either red or blue, then use the other of the two (i.e, if he starts with blue, red will be next and vice versa) and green vial will always be third. There will also be adds that have to be dealt with in a special way. Rinse and repeat until he gets to 25%.
Red Vial - During this phase he will do a flame breath on the tank, which does 750.000 damage split among the targets. This means everyone except the offtank tanking adds must stack up on the tank during this phase, or the tank will be one shot. The aoe damage isn't too horrible if everyone is stacked up, so keep some healers to focus on tanks at all times. Especially the add tank can drop low when you least expect it.
Blue Vial - During this phase he will randomly ice block one person, dealing 50k damage, and the block will jump to any other target within 10 yards, also dealing 50k damage, so have everyone spread out enough to avoid this. The target in the ice block must be freed. The ice block only has 5k hp, so this is easily done by just about anyone, but when the ice block breaks whoever is in it, and any target within 10 yards will take an additional 50k damage. Breaking the target free asap isn't advisable, you must make sure he'll survive the extra 50k damage first so communication is imperative. Deal with this as you would a mix of the blocks on Sindragosa and Kel'Thuzad. You could have a healer focus on the ice blocked targets (as one usually had on Kel'Thuzad). He will also put a dot debuff on a random player, which will deal a low amount of damage to the target and anyone else within 8 yards.
Green Vial - Maloriak will throw a debuff on the entire raid, and all adds, that make them take 100% more damage. This is the phase in which you will nuke down the adds, so have the offtank(s) gather them up for everyone to aoe. Maloriak will also buff himself with a spell called Remedy, which must be dispelled/spell stealed asap as it heals him for a million hp each second, this could make or break a try.
Adds - Maloriak will spawn 3-5 sets of 3 adds each phase. We had different amounts for some reason, so this is a factor that could make the fight easier or more difficult. There are 18 adds at the beginning and when Maloriak reaches 25% he will release all the remaining adds. You want to get rid of all the adds before 25%, which means you have to release 9 before each green vial (this is what you have time to do before the enrage timer). Our tank couldn't take the damage from 9 adds, so we had our Feral Cat Druid tank up the last 3. Whether you use one or two offtanks is really up to you and what your raid could handle. We chose to use two, or maybe rather one and a half.
Let Maloriak spawn 9 adds between the red and blue phase and make sure to interrupt the subsequent casts. Have the offtank(s) kite them around (making sure not to be ice blocked with someone during the blue phase) and kill them off during the green phase. Do this again for the next red and blue phase.
Each add has a buff that makes other adds in the vicinity hit 20% harder and take 20% less damage, so the more they get the harder they hit. This also means you never should let the adds get close to Maloriak who also can be affected by this buff.
Arcane Storm - Throughout the fight, until he reaches 25%, Maloriak will use Arcane Storm, a really nasty aoe that needs to be interrupted asap.
25%-0%
Once Maloriak reaches 25% he will go into soft enrage, releasing all the remaining adds (which all should be dead) and two additional bigger and meaner adds. The bigger, meaner adds will fixate on someone, but they could be tanked as usual. It is recommended that you have the offtank do this because they hit hard and will hamper the raid if the roam free. Same deal with these adds, tank them away from Maloriak or else they will make him hit 20% harder and take 20% less damage. Maloriak has some new skills during this phase;
Magma Jets - A sort of flame wake targetted at a random player that deals damage and leaves a dot. Move away from it. You will notice him doing hit by him raising his hands. Even the tank must move away from it.
Absolute Zero - An ice sphere that deals a little damage and does a knock back. I honestly didn't notice this once during the fight, but keep an eye out for it nonetheless.
Acid Nova - Aoe damage that needs to be healed through.
Each of these skills aren't difficult, it's just if one person happens to get them all at once that you'll have a problem.
Priest Specific
The trickiest part of this fight was keeping the various tanks alive. The addtank(s) could really take alot of damage and you had to be on your toes at all times. Boss tank too could take some heavy blows occasionally. This made me really love Holy Word: Serenity, which also worked wonders on the ice blocked targets. None of the other skills were very difficult to handle. The aoe damage on Magmaw is alot more difficult than the one on this boss so if you could down him you can handle this. Having one good aoe healer focus on raid during the red phase and the other two focus on the tanks is a good idea, depending on your healing setup.
As you can see from the recount, Heal was on top for the first time since I started raiding. This is because good single target healing is the key in this fight. Only in the final portion of the fight will you have to use both alot of aoe healing and single target healing, so make sure your healers know what to heal. I switched between using Chakra: sanctuary for red phase and Chakra: Serenity for the blue and green phase. Mana depended alot on how people handled stuff like the Arcane Storm. On some tries I had issues with mana, on our kill try I was at full mana when we got to 25% (but oom when he died). For some reason the resto druid kicked our asses in healing done. Shamans seem to have issues with healing overall at the moment (although our resto shaman was awesome), their throughput is generally lower than other healers right now. I think the reason is that when a fight is focused around single target healing, druids come out stronger. Holy priests still seem to excel in aoe healing.