The Four Horsemen each have approximately 781,000 hit points. They will run into separate corners of the room when engaged.
Thane Kor'Thazz
A former dwarven king turned Death Knight. Melee fighter. He will run into the near left corner of the room when engaged.
Meteor - 13775 to 15225 Fire damage split between all players in an 8 yard radius. Cast every ~15 seconds.
Mark of Kor'Thazz - Cast at random intervals. Stacks infinitely. The first stack will do 0 unresistable shadow damage. The second 500. The third 1500. The fourth 4000. The fifth 12,500. The sixth 20,000. The seventh 21,000. The eighth 22,000 and so on increasing by 1,000 every subsequent mark. While the initial damage caused by the application cannot be resisted, the application of the Mark can be resisted. 45 yard range. 25 second duration. Marks hit everyone in range and will reduce the threat on the Horseman of everyone hit by 50%. Should there be no one in range in the raid to receive a mark the entire raid will instead be hit by a very powerful AoE. Mark of Kor'Thazz will be cast at the same time as Mark of Rivendare, but at a higher frequency than the Mark of Blaumeux and Mark of Zeliek.
Baron Rivendare
A male human Death Knight. Melee fighter. He will run into the near right corner of the room when engaged.
Unholy Shadow - 2160 to 2640 Shadow damage to his primary aggro target. Applies a dot which does 4,800 shadow damage over 8 seconds. Cast every 15 seconds.
Mark of Rivendare - Cast at random intervals. Stacks infinitely. The first stack will do 0 unresistable shadow damage. The second 500. The third 1500. The fourth 4000. The fifth 12,500. The sixth 20,000. The seventh 21,000. The eighth 22,000 and so on increasing by 1,000 every subsequent mark. While the initial damage caused by the application cannot be resisted, the application of the Mark can be resisted. 45 yard range. 25 second duration. Marks hit everyone in range and will reduce the threat on the Horseman of everyone hit by 50%. Should there be no one in range in the raid to receive a mark the entire raid will instead be hit by a very powerful AoE. Mark of Rivendare will be cast at the same time as Mark of Kor'Thazz, but at a higher frequency than the Mark of Blaumeux and Mark of Zeliek.
Lady Blaumeux
A female human Death Knight. Ranged combatant. She will run into the far left corner of the room when engaged.
Shadow Bolt - Instead of melee-ing Lady Blaumeux will chain cast this on the closest player to her. 45 yard range 2 second cast 2357 to 2643 Shadow damage.
Void Zone - Summons a void zone on a random player within 45 yards that does 2750 Shadow damage per second to anything within it. Cast every 15 seconds. Lasts 75 seconds.
Mark of Blaumeux - Cast at random intervals. Stacks infinitely. The first stack will do 0 unresistable shadow damage. The second 500. The third 1500. The fourth 4000. The fifth 12,500. The sixth 20,000. The seventh 21,000. The eighth 22,000 and so on increasing by 1,000 every subsequent mark. While the initial damage caused by the application cannot be resisted, the application of the Mark can be resisted. 45 yard range. 25 second duration. Marks hit everyone in range and will reduce the threat on the Horseman of everyone hit by 50%. Should there be no one in range in the raid to receive a mark the entire raid will instead be hit by a very powerful AoE. Mark of Blaumeux will be cast at the same time as Mark of Zeliek, but at a lower frequency than the Mark of Kor'Thazz and Mark of Rivendare.
Sir Zeliek
A former paladin turned Death Knight. Ranged Combatant. He will run into the far right corner of the room when engaged.
Holy Bolt - Instead of melee-ing Sir Zeliek will chain cast this on the closest player to him. 45 yard range 2 second cast 2357 to 2643 Holy damage.
Holy Wrath - Deals 900 to 1100 Holy Damage to a random player within 45 yards. Can jump to any player within 10 yards and continue jumping, increasing in damage by 50% every jump with no limit. Cast every 15 seconds.
Mark of Zeliek - Cast at random intervals. Stacks infinitely. The first stack will do 0 unresistable shadow damage. The second 500. The third 1500. The fourth 4000. The fifth 12,500. The sixth 20,000. The seventh 21,000. The eighth 22,000 and so on increasing by 1,000 every subsequent mark. While the initial damage caused by the application cannot be resisted, the application of the Mark can be resisted. 45 yard range. 25 second duration. Marks hit everyone in range and will reduce the threat on the Horseman of everyone hit by 50%. Should there be no one in range in the raid to receive a mark the entire raid will instead be hit by a very powerful AoE. Mark of Zeliek will be cast at the same time as Mark of Blaumeux, but at a lower frequency than the Mark of Kor'Thazz and Mark of Rivendare.
Note: Thane Kor'Thazz and Baron Rivendare will both cast their marks in unison, while Lady Blaumeux and Sir Zeliek will both cast their marks in unison. Because of Lady Blaumeux and Sir Zeliek's lower casting frequency, it is completely possible for their Mark debuffs to wear off and reset the stack counter.
After 100 marks have been cast the Horsemen will berserker enrage increasing all damage done by 1,000%. After a Horseman 'dies' it will stop casting all abilities except Horseman marks and will only melee if a target is within melee range. The encounter ends when all Four Horsemen have been slain.
Strategy:
Engaging begins when the ‘back team’ runs across the platform. The Horsemen will automatically run to their corners, the raid will split into 3 groups one for each front Horseman and 1 for the back 2. The back healer can remain in the middle without taking mark stacks and heal their 'tanks'.
Rivendare and Kor'Thazz Groups - These will consist of a tank, 1 healer and half the DPS in each.
Zeliek and Blaumeux Groups – These 2 mobs are stationary once they run to their corners. 2 ranged dps, ideally able to heal themselves and 1 healer, our back group is usually Holy paladin, lock, and a hunter.
Each group will run to their Horseman. The Kor'Thazz and Rivendare groups should stack up on their tank. The Zeliek and Blaumeux groups should be at max range in between Zeliek and Blaumeux. Every three marks the Kor'Thazz and Rivendare groups will switch places and the Zeliek and Blaumeux groups will switch places on their marks, not the front groups.
At every 3rd Mark, Kor'Thazz and Rivendare tanks should drag their Horseman to each other and taunt off each other, then drag their new Horseman back to their corner. Because of Meteor both groups will need to remain stacked on their tank.
The Zeliek and Blaumeux ranged tanks should start running for each other's position as soon as the third mark goes off.
After Kor'Thazz and Rivendare are dead their groups will switch to Zeliek and Blaumeux, remember to stay spread out on Zeliek and be careful of Void Zones on Blaumeux. You will still need to switch sides every 3 marks. EVERYONE IS RESPONSIBLE FOR THEIR OWN MARKS AT THIS POINT. Keep in mind they will target the closest player to them with their nukes.
Kill her, then him.