Chromaggus

Clear up to Chromaggus (see Ebonroc on how to kill the Wyrmguards) then have your raid buff up. This fight has variables that can help or go against you, so be ready for a moderately easy too extremely difficult fight.Position your raid like in the diagram above, with your casters up against the wall. Diagram

Breaths

Every 30 seconds he will “breathe” a different spell that will do a large amount of damage to anyone in LOS of him. He has several different breaths but will only use two of them, in alternating order.Frostburn: Manaburn with 5k frost damage (roughly). It also slows you for 5 seconds.Corrosive Acid: 875-1125 damage every 3 seconds for 15 seconds plus 3938-5062 armor reduction for 15 seconds.Time Lapse:  This one is a tough one and an easy one, it basically reduces everyones health by 50% and stuns them. Everyone needs to get hit by Time Lapse except one off-tank who moves into position to tank Chromaggus and the off-tank healers.Ignite Flesh: A nasty one, does 657-843 damage every 3 seconds for 60 seconds and is made worst by the Brood Afflection: Black! Lots of heals on the main tank for this one as he’ll have it on him for the duration of the fight.Incinerate: An easier one, does 3500-4700 fire damage negated by resists.

Brood Afflictions

He will randomly cast a various “Brood Affliction” on anyone in the raid. All of them can be cleansed with the various Priest, Druid, and Paladin cleansing spells except for Bronze which can only be cleared by Hourglass Sand (which should be given to off-tanks (for Time Lapse), Hunters, and the Main Tank.

Warning! If five of these stack up then the person will turn into an evil dragon and attempt to kill your raid, which needs to be dealt with by a tank and all of your DPS. THIS SHOULD NEVER HAPPEN!

Brood Affliction: Bronze – Stuns you for 4 seconds periodically, so unless you are a Hunter or tank with Hourglass Sand just get out of the way of breaths faster then normal. This can only be dispelled with Hourglass Sand
Brood Affliction: Red – Deals 50 damage every 3 seconds and if you die while under it you will heal Chromaggus. Disease and stackable.
Brood Affliction: Black – Increases fire damage by 100%, bad for some of the breaths.  Curse.
Brood Affliction: Green – Deals 250 damage every 5 seconds, this is a poison and easily removed.
Brood Affliction: Blue – Burns 50 mana every second and increases casting time by 50%. Very bad and should be a priority to remove. Magic debuff.

Frenzy

Well, even with all of this bad stuff, guess what! Chromaggus will randomly frenzy in which you will need a Hunter to tranq shot. So set-up a tranq shot rotation and ensure your Hunter’s have frenzy.

The Fight Itself

The fight consists of  your ranged DPS and rogues hiding behind the wall (in the diagram) until CT_Raid alerts you that Chromaggus has breathed. Once he’s breathed then your Rogues need to move into melee range and your ranged need to move back from the wall. Your healers should be able to stay at the wall and heal the main tank no matter what. Spot heals on the raid itself should be possible as well, but people should bandage themselves if they get into trouble.So basically the main tank tanks Chromaggus while everyone DPS until about 7 seconds before a breath where they run for safety and out of line of sight then, after the breath, move back into range.For Time Lapse though it’s a little different. Everyone needs to get hit by Time Lapse while your off tank (who builds aggro up through the fight) and off-tank healers hide behind the wall. When Time Lapse goes off the off-tank goes in and tanks Chromaggus until it wears off, using Taunt if necessary to hold aggro.

At 20% Chromaggus gets angry and becomes enraged increasing the rate in which he hits. Have all of your Warriors execute and just “burn him down”. Once he’s dead the gate to Nefarian will open.