NB: The Cataclysm strategies are based on a mixture of beta reports and may or may not bear any resemblance to the fight on Live.
If you spot major differences, post them in the comments and I can update the strats. I’ll be updating these myself as my guild begins raiding in Cataclysm.

Tanking: Only 1 tank is needed for this fight. Tank Atramedes in the middle of the room.

Healing: Some times of high raid damage, but this does not seem like an especially demanding fight otherwise.

Positioning: Atramedes should be tanked in the centre of the room, and the raid spread out around him. There is no cleave or tail swipe to worry about.

Buffs: Arcane, Fire and Shadow resistance are useful.

Key Debuffs: –

HP: 97,980,000 (32,638,000 on 10-man)

Enrage: Soft – when all the shields are used up you will wipe on the next special ability.

Bloodlust: The shield gives Atramedes Vertigo, increasing his damage taken by 50%, so ideally BL would coincide with this. Otherwise, Phase 1 looks to be a better time due to less movement.

Atramedes is a blind dragon, so the whole fight depends on preventing him from noticing you. Each raid member has a “sound” bar: when this reaches 100, Atramedes will detect that player and kill them quickly and unavoidably. This is an execution encounter, keeping your Sound as low as possible.

Sound can be reset using one of the 8 gongs in the room, but these will be needed to interrupt certain special abilities, so they shouldn’t be wasted early.

The fight has two phases which repeat: you start in a ground phase, and later on transition to an air phase.

Phase 1 – Ground – 80s Duration

Atramedes will be tanked in the middle of the room, and the raid needs to spread out all around him.

The two main things to avoid are the Sonic Breath and Sonic Pulse.
The Sonic Breath is targeted on a random raid member and hits everyone in its path, dealing 20,000 Fire damage and adding 20 Sound per second to anyone hit by it. It may move in a random direction, so stay well away from the target and avoid the Breath.
Sonic Pulse spawns 3-4 discs of sonic energy which move around the room. Anyone hit by them will take 3,000 Arcane damage and recieve 7 Sound.

Apart from this, Atramedes will periodically increase everyone’s sound by 7 with Modulation. Modulation also deals 40,000 Shadow damage.

The important ability to react to is Searing Flames. This fires meteors randomly around the raid which deal Fire damage and add 10 Sound per hit, as well as stacking a +25% Fire damage taken debuff. This lasts 8 seconds and should be interrupted immediately by a gong, because it can be seriously disruptive to the raid.

Phase 2 – Air – 40s Duration

Sonic Pulse continues to apply in this phase, so everyone needs to keep avoiding the sound discs.

To complicate things, Atramedes will cast Roaring Flame Breath at the highest Sound player, following them and increasing in speed over time. If this touches the player they will take 15,000 Fire damage and add 10 Sound every 0.5 seconds, so they absolutely have to be kited for as long as possible. If the flames are about to reach someone, a gong should be used to interrupt them.

The raid also needs to stay at least 8 yards away from the Sonar Bomb, which will deal 30,000 Arcane damage and increase Sound by 30 to anyone caught by it, and must stay out of the Roaring Flames, which deal 15,000 Fire damage and leave a DoT that ticks for 8,000 Fire damage per second for 4 seconds. The Roaring Flames also add 5 Sound.

Finally, every 10 seconds Atramedes will cast Sonic Fireball on a random player, dealing 30,000 Fire damage to anyone within 6 yards of the target, but does not apparently add any Sound.