Felmyst is the third boss in Sunwell Plateau. She spawns following Brutallus' death and flies around the Dead Scar.

Raid Setup

9 Healers
2 Tanks
14 DPS

At least 3 priests should be included, preferably 2 or all 3 being shadow priests, for Mass Dispel. A protection paladin will make Phase 2 significantly easier; many would regard a protection paladin as a requirement for this fight.

Buffs and Consumables

The raid must go for maximum DPS and mana regeneration depending on class, spec and role. Healers and Area of Effect (AoE) DPS will need mana regeneration if a shadow priest is not available. This means flasks or elixirs depending on your needs, weapon oils/stones, Destruction Potions, Drums of Battle/Restoration, etc. Tanks will want Flask of Fortification, 30 stamina food, and Ironshield Potions.

Gear Requirements and Notes

The only gear requirements are what is needed to kill Brutallus. The main tank does not wear nature resistance gear. A run speed increase to boots enchantment or minor run speed meta gem is highly recommended for everyone because of the fast position changes required in the fight.

Abilities (Split by Phase)

~7 million hit points

Phase 1

Melee
~5-7k damage
~2 second swing timer

Corrosion (Nature)
This ability is used on Felmyst's main aggro target only. It deals around 10k nature damage, which averages to just over 8k on a protection warrior with 3/3 Improved Defensive Stance. It has a 0.75 second cast time, is not reflectable of resistable, and also increases the target's physical damage received for 10 seconds.

Noxious Fumes (Nature)
An aura of Felmyst's that hits everyone in a 100 yard radius, ticks every 3 seconds, and deals 1,000 damage a tick. It is not resistable.

Gas Nova (Nature)
Gas Nova places a debuff on the entire raid which ticks every 2 seconds, dealing draining 1000 mana and 3000 health. It has a 1 second cast time, a 20-25 second cooldown, and can be dispelled, but is not resistable.

Encapsulate (Arcane)
This ability has a 25-30 second cooldown. Felmyst will turn and Encapsulate anyone in the raid for 6 seconds, placing a pink glowing sphere around them, and dealing 3500 damage every 2 seconds to that person, and everyone in a 20 yard range of them. The Encapsulate itself cannot be out ranged, and only Iceblock, Cloak of Shadows and Divine Shield remove it. During the spell, Felmyst channels a pink beam at the target.

Cleave (Physical)
A frontal attack, hitting all players immediately in front of Felmyst for around 7k damage.

Phase 2

Demonic Vapor (Nature)
A green beam fired by Felmyst at a random target, and chasing them for around 10 seconds at around normal player running speed, spawning skeletons as it goes. It applies as DoT that deals 2-2.5k damage a tick for 10 seconds if you standing in it or its trail and spawns an extra skeleton. Each skeleton has around 33,000 health.

Dusting/Green Vapor
Felmyst breathes this over a third of the fight area three times in Phase 2. The vapor mind controls anyone that enters or is hit by it for the entire duration of the fight. Mind controlled players are slightly buffed, and cannot be released from the mind control, only killed.

Both Phases

Noxious Fumes (Nature)
An aura of Felmyst's, this hits everyone in a 100 yard radius, ticks every 3 seconds, and deals 1,000 non-resistable damage per tick. This is unavoidable given the massive range of the spell.

Sunwell Radiance
Chance to hit increased by 5%.
Enemy chance to dodge reduced by 20%.
This buff is currently active on all NPCs in Sunwell Plateau, including bosses, it seems intended to balance encounters against high avoidance tank gear. It also makes the rogue ability Evasion less effective. It does not require any particular raid strategy to counter, but tanks and rogues should be aware of it.

Enrage - 10 minutes
Felmyst will gain a 500% damage increase on all her abilities.

The Pull

Do not use any AoE abilities. This will engage Felmyst if she flies overhead.

Let the tank shoot or throw to engage Felmyst. A Misdirection should follow, and be completed, before her actual landing. The main tank can build threat before Felmyst lands and begins using her abilities. He will then begin tanking her directly south of the large tree.