Warmaster Blackhorn is the 6th boss of the Dragonsoul, he consists of two phases and has 3 main abilities; Devastate, Disrupting Roar, and Shockwave.
The Warmaster isn't attackable in phase one, instead, he flies above you and spawn adds and twilight dragons to attack the boat. Along with that, he try to wreck the boat by using meteors and explosives.
There are two type of meteors, minor ones, and major ones. The minor ones can be soaked by one player, but the major ones needs to be soaked by the entire raid to avoid deaths. It's very easy to see which is which as there'll be effects on the ground to identify them with. The Warmaster will also send NPCs called "Sappers" onto the boat and they carry explosive, they need to be killed off quickly before they reach the cabin - they deal a great amount of damage to the boat. Sappers do not exist in LFR difficulty.
Melee DPS should focus on killing the melee enemies, and the ranged should prioritise to kill the twilight drakes, then help the melee. This is a rinse and repeat phase until phase two starts.
When phase two starts the Warmaster will board the boat and attack.
• Devastate deals 120% weapon damage and reducing the player's armor by 20% for 30 seconds and this effect stacks, I strongly suggest you to tank swap at max 2 stacks to play it safe.
• Disrupting Roar is a roar which deals phyical damage to the entire raid and it will interrupt anyone who's currently casting a spell within 10 yards for 8 seconds. Do not stand close to him.
• Shockwave is almost like Devastating Slam in Zul'Gurub. The Warmaster will target a random player and cast a shockwave (yes I said cast), you have to be quick to get out of its frontal cone. This ability is critical and will most likely kill you if hit.
• Vengeance is something the Warmaster gains during the encounter, he will inflict 1% more damage for each percentage of his missing health. Pain Supression and Hand of Sacrifice will be sweet towards the end.
Q: How many tanks do you need for this fight?
A: You require two tanks.
Tips & Tricks
• The Warmasters roars are physical damage and it deals alot of damage. Don't be afraid to use a cooldown.
• Feint works to reduce the damage of meteors.
• Shadow Priests can soak the major meteors alone with Dispersion
• If you're a Priest and you just love to annoy people with Leap of Faith, this encounter is no good for you. Players who aren't paying attention to the Warmasters shockwave will appreciate a grip to survive.