Mythrax swaps between two stages every 25% health lost.
A stacking debuff that is applied when players get hit by various mechanics throughout the encounter. Reduces maximum health by 1% and deals 1,370 magic damage every 3 seconds per stack.
An Existence Fragment will spawn near anyone who gains stacks of Annihilation, and touching it will consume the fragment and remove 2 stacks of Annihilation. When Mythrax reaches 10%, he casts Essence Shatter, which prevents Existence Fragment generation for the rest of the fight.
Stage One: Oblivion's Call (100% & 50%)
Essence Shear (TANK)
A 15 yard frontal cone which deals ~55,000 magic damage and applies significant Annihilation to anyone hit, also removing the ability to generate Existence Fragments for 25 seconds. Swap on one and the tank hit should go clear their stacks of Annihilation.
Purple spheres will spawn on random players, charming any players in contact with them and applying a stack of Annihilation every two seconds. Affected players will remain charmed until the sphere is killed, or if they are knocked away from the sphere, which can be done by dealing damage to the affected players or using knock back spells. Each player that is freed will trigger ~15,000 magic damage (Crashing Oblivion) to the entire raid.
A debuff placed on two random players which deals ~7,000 magic damage every 2 seconds for 12 seconds. Upon expiration, applies Annihilation to everyone within 12 yards of the affected player. Also deals ~30,000 magic damage to the entire raid on expiration, decreasing the farther away players are from the explosion. Affected players should run in different directions away from the raid until the debuff expires.
Mythrax shoots out a huge shadowy wave, dealing ~46,000 magic damage and applying Annihilation to anyone hit. Fatboss had raid members get hit by this on purpose to generate extra Existence Fragments for tanks and players with high stacks of Annihilation.
Stage Two: Ancient Awakening (75% & 25%)
When this stage begins, Mythrax will go into the middle of the room and become surrounded by a force field, reducing damage taken by 99%. Anyone who enters the force field will take ~31,000 magic damage every 3 seconds (Oblivion Veil).
Two Oblivion Spheres will also spawn, so the raid must remain spread as they see the transition happening. Eventually an eruption will occur dealing ~30,000 magic damage to and applying Annihilation to the entire raid and stage two begins.
Visions of Madness
Clones of 5 players will spawn and begin channeling Mind Flay on random players, which deals ~5,000 magic damage every second and reduces movement speed by 50%. Stuns and interrupts should work, and these adds should be burned down quickly.
After a short cast Mythrax shoots a massive beam across the room and begins rotating, dealing ~8,000 magic damage and applying Annihilation every 0.3 seconds to anyone hit. Players need to be quick to react to the cast as the damage is basically fatal.
These two big adds spawn shortly after the stage begins and must be tanked 40 yards apart or will deal 80% increased damage and take 80% decreased damage. They cast Void Volley, which deals ~29,000 magic damage to the raid, but can be interrupted. They also cast Essence Shear (TANK) like Mythrax in Stage One, so must be burned down as quick as possible.