The Arcatraz

This fight is rather easy, the only real strategy required is to interrupt the rather pathetic heal she casts after whirlwind and to avoid healing except when absolutely necessary anyone afflicted by "Gift of the Doomsayer." This can and will be cast upon the tank, try and save any defensive boosts/trinkets for when this hits your tank and they should be able to go for quite some time without needing a heal.

Wrath-Scryer Soccothrates

Abilities

Knockback: Deals quite a bit of damage and a huge knockback

Charge: Randomly used

Felfire Shock: Hits targeted player for around 1400-1600 damage, deals more fire damage every 3 seconds

Felfire Trail: Leaves a trial of felfire behind the boss, deals 2000 or so damage a second whilst within the fire

Immolation: Deals 832-918 damage every 3 seconds

Fight

Soccothrates is quite the challenging fight, a combination of his immolation and felfire abilities can annihilate almost anyone in a small amount of time. The tank can engage and hold him where he stands, the boss should begin nuking you with immolation shortly after you engage as well and perhaps hit the tank with felfire shock.

When the boss casts the felfire trail spell your tank should maneuver as needed to maintain his position out of the fire but still tanking the boss, everyonce in a while he'll also have to re-engage after a knockback. Continue to be prepared for each of these abilities and the boss should go down eventually.

Harbringer Skyriss

Abilities

Mind Control: Takes over a random party member for a short time

Clone: Summons an elite version of the boss, this clone has a much lower HP than the original

Mind Burn: Deals 1200-2000 damage to random party members

Fight

This boss fight is rather different than the usual, the event will begin when you approach the blood elf channeling into the pod. Each pod contains a monster that you will be required to defeat.

Pod 1:

This pod contains an elite imp, the imp will deal medium fire damage but remains an easy kill, as soon as the imp goes down I recommend drinking/eating if needed.

Pod 2:

Millhouse the lost gnome mage comes out of this pod, he'll help you defeat the next few pods.

Pod 3:

This spawns what is basically sulfuron, similar to the sulfuron in molten core. He'll use all his old abilities including his debuff and rain of fire spell, just avoid the AoE and kill him, also watch out for millhouse, don't allow him to die. As mentioned above eat/drink after sulfuron goes down.

Pod 4:

This spawns an elite dragonkin mob, a simple tank n'spank fight, just have your tank hold him with his back against the wall and DPS him down. Does some large melee damage but if you can heal through that it should be no problem. Yet again, drink/eat up after this, also don't let him wack millhouse.

The boss:

Harbringer is a boss somewhat similar to Skeram, the first boss from AQ40, and uses a few somewhat similar abilities to boot. Fighting this guy is somewhat simple due to his tank n'spank nature yet and ill-timed Mind control and the mind burns can wear you down. The real trick to this fight is to watch out for his cloning ability, every once in a while the harbringer will clone himself, whichever harbringer your tank is on, the real one, and kill the clone(newly summoned fake harbringer.)

If your party is able to keep up the DPS and kill the clones in a good amount of time you'll survive.

Zereketh the Unbound

Abilities

Seed of Corruption: Similar to the warlock spell, deals 400 damage every 3 seconds, once the target has taken 2500 damage the seed detonates, dealing a large amount of damage within 10 yard of the afflicted player

Unbound Void Zone: Randomly targeted within the room, deals 1400-1600 damage a second to anyone within range

Shadow Melee: All melee damage dealt by Zereketh is shadow, deals 1200-2000 or so a hit

Shadow Nova: 40 yard AoE knockback nova attack, deals around 2000-2400 damage

Fight

After reading his abilities it should be somewhat obvious what buffs you need, shadow protection or a paladin aura at least. Beyond that the boss is a somewhat easy fight, his void zone spell appears as a black circle on the ground, quite easy to spot, and seed of corruption is weak, just move out of range when it's about to go. Finally the shadow nova is left unspammed thankfully, just beat him down.