Raid Setup
The raid setup in this encounter is quite flexible so you can switch it out to whatever fulfils your needs.
Tanks: 2 (1 main tank warrior and 1 Soul Link warlock in the same group who will act as offtank, preferably with a paladin in the group. If no paladin is available, with a shaman.)
Healers: 7 (1 healer for each group, with 2-3 focusing on the main tank and the warlock offtank + his pet.)
DPS: 16
Buffs and Pots
All standard buffs, potions and flasks.
The warlock offtank needs to be Soul Link specced and have about 300 unbuffed fire resistance and as much stamina as he can get. The warlock needs a shaman or a paladin in his group with Fire Reistance Totem/Fire Resistance Aura and a Flask of Fortification.
A Limited Invulerability Potion can also come in handy to everyone in dealing with the Phase 1 ability Whirlwind: it removes the Rend and saves the healers some healing aggro.
Boss Abilities
Health - 2,300,000
Enrage - 10 minutes.
Whirlwind
Humanoid Form Ability. Leotheras will start running around Whirlwinding, much like Warchief Kargath Bladefist from Shattered Halls or Sartura from Ahn'Qiraj 40. The Whirlwind does 3,000 physical damage to anyone it hits, and also applies a non-dispellable DoT (Damage over Time debuff) called Rend, that deals 2,500 physical damage every 3 seconds, which is removable by Divine Shield, Blessing Of Protection, Limited Invulnerability Potion and Ice Block. He will do another Whirlwind 20 seconds after the first one ends. He will reset his aggro on every Whirlwind. Leotheras should not be attacked by anyone except the MT during the Whirlwind.
Chaos Blast
Demon Form Ability. A bolt that does about 100-200 Fire damage to the target and everyone in a 10 yard range of the target. This base damage is insignificant, however it also gives a debuff that increase fire damage taken by 1,675, and this debuff stacks up to 5 times.
Inner Demon
Demon Form Ability. Summons an Inner Demon of a few random people in LoS (Line of Sight). The demon has as much health as the person it has spawned from. Each Inner Demon can be attacked only by the person it spawned from. If you do not kill your Inner Demon before Leotheras gets back into humanoid form you will become Mind Controlled for 10 minutes and can't get out of it. If you're killed while Mind Controlled, you cannot be resurrected for the duration of the fight. The demons hit for roughly 1,000 on mail and shoot out Shadow Bolts dealing around 2,500. This ability will not be cast on the current tank, be it the MT or the warlock offtank.
Note that your Inner Demon, if you have one, will be rendered normally, whereas the Inner Demons of other players will appear as black silhouettes.
Strategy
Phase 1
Humanoid Phase, lasts about 1 minute.
The first Phase 1 begins by pulling the 3 adds banishing Leotheras. Each of them needs to be tanked and killed. They do 3k Mind Blasts to random people in the raid every few seconds. They're nothing serious. After they're dead, Leotheras will become active in his humanoid form (this is the point from which the 1 minute phase duration is counted). He should be Misdirected to the main tank who's waiting at the tanking spot.
About 15 seconds after the beginning of the fight he will reset his aggro and start to Whirlwind around for about 10 seconds. You need to be spread out and keep moving away from him to avoid getting hit. Be very careful when healing in this phase as you do not want to accumulate much aggro on Leotheras and have him kill you once he's done Whirlwinding. If you're a non-healer do not drink any healing potions so as not to risk getting any aggro on him. The tank needs to follow him around and grab him as soon as he's out of the Whirlwind and accumulate aggro. Nobody attacks him for at least 5-6 seconds after he's stopped so the tank can hold aggro. 15 seconds after he's stopped the first Whirlwind he'll wipe his aggro again and do another Whirlwind. After he stops, he'll be as normal for about 10 seconds then switch to his demon form and wipe aggro again, starting Phase 2.
Phase 2
Demon Phase, lasts about 40 seconds.
Leotharas turns into a demon and remains stationary while shooting out Chaos Blasts on his target. In this phase, the warlock offtank tanks Leotheras from range so that melee DPS can still attack him without being hit by Chaos Blast.
The offtank warlock needs to use Searing Pain to grab and hold aggro on Leotheras. It doesn't really matter where the warlock stands as long as there it is clear of Leotheras and there isn't anyone in a 10-15 yard range of him. Everyone needs to be well clear of the offtank warlock to avoid being hit by Chaos Blast, which Leotheras will start casting on the warlock. 15 seconds into the fight he'll summmon Inner Demons for some random people in Line of Sight. If you're a healer and you don't think you have enough DPS to kill your Inner Demon, you can hide behind the big "Pillar" in the middle of the room when Leotheras summons them. After the 40 seconds are over, he'll go back into his humanoid form.
He will rotate between Phases 1 and 2 until he's at 15%. This is when Phase 3 starts.
Phase 3
Humanoid and Demon Phase.
At 15%, his demonoid form will split from his humanoid form, leaving you with 2 bosses to fight. His demon form needs to be tanked again by the offtank warlock, with nobody in a 15 yeard range of the warlock. His demon form will be the same as in Phase 2, except he won't do Inner Demon anymore. His humanoid form needs to be tanked by the main tank warrior again and it will act the same way as in Phase 1, opening with a Whirlwind and repeating it every 15 seconds just like in Phase 1. However, you won't really have enough time/survivability to see more than 2-3 Whirlwinds no matter what you do. You need to nuke down his humanoid form as fast as you can, as he will be near his enrage point now. As soon as his humanoid form dies, the fight is over and the demon form vanishes.
Class Assignments
Main Tank
Tank Leotheras in the middle of the room at the designated spot. After the Whirlwind is over, you need to grab him as fast as possible and reposition him in the middle again.
Warlock Offtank
You can start the fight with a Curse of Doom on Leotheras so that it can tick off for extra aggro during Phase 2. When Phase 2 hits, you have to nuke him with Searing Pain and keep aggro on him for the duration of the phase. In Phase 3 you need to keep aggro on the Demon version of Leotheras until his humanoid form is killed.
DPS Warriors, Feral Druids
- In Phase 1, you need help tank the initial adds. After they're dead revert to a melee DPS role.
Melee DPS
DPS Leotharas from behind and spread out when he starts to Whirlwind. Do not use healing potions if hit by Whirlwind. Stop DPS for 5 seconds after he's stopped Whirlwind so the tank can accumulate aggro on him. In Phase 2, keep DPS-ing Leotheras and kill your Inner Demon as fast as possible. In Phase 3, DPS the humanoid Leotheras with every cooldown you have.
Ranged DPS
Spread out around the room and DPS Leotheras. Do not use healing potions if hit by the Whirlwind. Stop DPS for 5 seconds after he's stopped Whirlwind so the tank can accumulate aggro on him. In Phase 2, keep DPS-ing Leotheras as much as you can and kill your Inner Demon as fast as possible. In Phase 3, focus DPS on humanoid Leotheras and burn every cooldown you have to kill him.
Healers
In general focus healing on your groups. However, if you see someone taking damage and not getting healed, help out as needed. While Whirlwinding, the only people who should be healing are the Paladins and Druids and maybe Priests with Renew and Fade. The tank group healer should focus on keeping up the MT in Phase 1, and the warlock in Phase 2. If needed, assign 1 more healer to the warlock. In Phase 2 if you don't think you have enough DPS to kill your Inner Demon, hide behind the pillar, but be careful not to let your group members die while you're out of Line of Sight/Range of them. In Phase 3, you'll need to be extra focused and keep healing people up as they'll be taking a lot more damage.
Miscellaneous Notes
It's normal for the demon form to Chaos Blast 1 or 2 people before the warlock grabs aggro on him. Don't be concerned when this happens.
Have a Soulstone placed on the warlock in case he dies, so he can resurrect back up and re-grab aggro.
Often you will kill Leotheras either at the beginning of his enrage or just a few seconds before it. So if it happens, do not feel the need to change things round - you still have enough DPS for the fight.
By Fergie at Bosskillers.com
Snitch