Arguably one of the hardest bosses in Blackwing Lair and has slaughtered many guilds for quite some time before they learned the right strategy.
Essence of the Red: This is cast upon the raid at the start of the fight giving warriors infinite rage, rogues infinite energy and caster infinite mana.
Burning Adrenaline: This makes all of your abilties instant cast, it also makes you explode after 18 seconds killing everyone near you.
Fire Nova: Deals 500-1000 damage to the entire raid.
Flame Breath: Breath attack hitting everyone infront of him dealing around 5000 damage. Use FR gear.
(Click to Enlarge)
The small dots are where players will position themselves. The large ones are where they run to explode from BA(Burning Adrenaline.)
Red rectangle is Vael, yellow is warriors, purple is melee DPS, blue is Ranged DPS, teal is healers.
Mages, Warlocks, and Hunters stand under the balcony next to the door. If a Mage is hit with BA he blinks towards the wall and nukes Vael as much as possible. BA is a short range AoE and thus you dont hit any of your team mates. Warlocks and Hunters do the same thing as the mage and simply unload as much damage as possible before they die.
Have one priest per team to heal everyone to counter the DoT Vael casts on them. Paladins, Shamans, and Druids are the main healers since the priests are healing to counter the DoT.
Move in on Vael once the MT has gotten a few sunders off on him. Once the MT has his sunders on have the rest of the warriors go in and spam sunder in this order. Secondary tank goes in and sunders, 2-4 seconds later the 3rd tank goes in and so on.
Once the warriors have had a little bit of time to grab aggro the DPS moves in. Once the MT is BAed he will explode and Vael starts moving to the 2nd warrior you have to get him back to his original position immediately.
You should try and take him out before the 3 minute buff wears off or you will almost always wipe.