Read this page for boss abilities:http://www.wowwiki.com/Malygos_(tactics)#Attacks_and_Abilities
Composition: 1 MT, 3 healers including 1 restoration druid, 6 DPS including 1 or better 2 DKs. All raid members need >22k health buffed.
Pull and Positioning The tank picks up the boss and faces him away from the raid, placed on the edge between the inner and outer ring. The rest of the raid stacks in the centre.
Phases This is a 3-phase fight. Phase 1 needs to be complete by the 4 minute mark, phase 2 by the 7 minute mark in order to beat the 10-minute enrage timer.
Phase 1 is all about pulling the Power Sparks to the same spot with Death Grip, then rooting them with stuns, Entangling Roots, Chains of Ice etc and DPSing them down in the same place every time as their +damage aura's that they leave behind when they die stack. The raid will stack in the middle and we'll take down the spark as it crosses the middle each time. The sparks are fully vulnerable to root and snare, Death Grip, Chains of Ice, Entangling Roots, Frost Trap, Concussive Shot, Mind Flay - they all work, use them wisely.
The tank needs to be watching all the time for where the sparks are coming from and moving the boss opposite to the spark, so the spark will always move through the raid. When turning the boss always make sure he faces away from the raid.
Arcane Breath does 20k+ damage to the tank, so the tank needs to be kept topped off.
Vortex does 20k over 10secs + 10% of max health as falling damage. As only instant cast spells can be used whilst in the air this strongly indicates that at least one of the healers should be a druid. DKs and Warriors should use frost presence or defensive stance respectively to reduce the vortex damage.
Phase 2 Begins when Malygos reaches 50%, he begins to take off, but is still targetable till he reaches maximum height, so burn him during this transition, all DPS use CDs.
Phase 2 is an add phase. There are two types of adds, Lords (melee) and Scions (casters) that ride around on hover disks. The Lords need to be tanked, and when killed will drop their hover disk which can then be used my melee to fly up and attack the Scions. We will determine an order for disk use, with melee going first. After melee have taken the disks if there are any spare then the tank may as well take one.
During this phase Malygos will drop Anti-Magic Zones on the floor, the raid needs to stay under these as they mitigate 50% of the Deep Breath AOE that the boss does, as well as the Scions' Arcane Blast. The AMZs shrink over time so the raid will need to move to a new zone after a Deep Breath. Warriors can use Spell Reflect to reflect the Scion's Arcane Blasts.
After the adds are dead, everyone must dismount, and druids must un-shapeshift. There is another short burn phase on Malygos who becomes targetable again, which DPS should use any remaining CDs as these will not be available once the raid are mounted.
Phase 3 Begins when all the adds in phase 2 are dead, and the floor breaks apart and the players fall to be saved by dragons from the red dragonflight. The abilities on these dragons are the same as in the daily Coldarra quest Ace's High - so go do this for practise. The drakes are like rogues, with energy and combo points.
2 people are designated healers, the rest are DPS. Everyone stacks up on the marked MT player (who is DPSing, as there are no 'tanks' per se in this phase) and strafes to the right every 3 or 4 seconds (stay stacked on the MT) - this is so that we're always moving out of range of the boss's Static Field AOE.
DPS: cast 5 Flame Spikes (does damage, awards combo points), then cast Engulf in Flames (stacking DoT), then cast Revivify (3-1-1-1-2), rinse and repeat. It is imperative to build and keep running your Engulf in Flames stack, as this is the only way to beat the bezerk timer. Casting Revivify in your rotation (key 3) will build and keep up 5 stacks of your HoT, which will keep you alive.
Healers: Build 5 stacks of Revivify then cast Life Burst (3-3-3-3-3-4), which will heal all nearby drakes (which should be everyone) for approx. 25% of their health. Rinse and repeat.
Everyone: Never let yourself get beneath 35 energy, that way you'll always have enough to get 1 combo point and be able to Flame Shield if you are the focus of Surge of Power.
When the boss focus's on you for Surge of Power you will get an emote on your screen (if you have no combo points then cast in order to get a combo point) and then AFTER the boss has cast Surge of Power put on your Flame Shield. The combination of your Revivify stack, the healers AOE heals and your Flame Shield will keep you alive. DO NOT use any abilities whilst Flame Shield is active, or you will lose it.
Every now and then, Malygos does Surge of power. It takes 3 seconds to cast, and players should always be prepared to be hit. Have combination points on Malygos and at least 25 energy points ready at all times to put up the Flame Shield once the Surge of Power hits. Have healers topping him up as well.
Note, for phase 3 players who use action bar addons such as bartender should do the Ace's High daily and make sure that the addon doesn't interfere with using their drake's abilities (just like in The Occulos) because sometimes bar mods can cause issues, and if you can't use your drake's abilities in phase 3 it's probably a wipe
Video here. Recommended viewing, especially for tanks.
P.S. HEROIC TARGET PRIORITY FOR PHASE 2: In 25-man, tanks and melee who are not yet on a disk should focus fire the Lords, while ranged focus fire the Scions from the beginning of Phase Two. (Of course, melee who get a disk transition to Scions.) This method consistently ends phase two 30-45 seconds faster than starting the phase with all dps on the Lords.