Forgemaster Garosh:

• Permafrost - Deals 200 Frost damage to all enemies nearby, increasing Frost damage taken by 10%. Instant. Magic debuff. Stacks 30 times. 400 damage/+20% a stack on Heroic. 3 second duration. Respects Line of Sight.
• Throw Saronite - 150 yd range — Throws a massive hunk of Saronite, dealing 3500 damage and knocking back any nearby enemies. 2 sec cast. 5,500 damage on Heroic. The resulting boulder blocks LoS of Permafrost and lasts five minutes.
• Thundering Stomp - Devastates all nearby enemies, incapacitating them briefly. Instant. Cast when Garfrost is at 66/33% health before jumping to one of his anvils. 2 second stun

Phase 2:

• Forge Frozen Blade - Forging an icebound weapon, which will increase Frost damage by 50%. 4 sec cast. Used at 66%. +100% Frost Damage in Heroic. Lasts all of phase two
• Chilling Wave - 40 yd range — A cascade of frozen water splashes over enemies in a 65 yd cone in front of the caster, dealing Frost damage. Instant. 1850/2000 Frost damage per second.

Phase 3:

• Forge Frostborn Mace - Forging an icebound weapon to trump all others. 4 second cast. Used at 33%. +100%/200% Frost Damage. Lasts all of phase three.
• Deep Freeze - Chills a random target, reducing movement speed by 50% and dealing significant Frost damage after 14. 2 second cast. Cannot be dispelled. Hits for 4,000/6,000 damage and stuns for 1 second after 14 seconds.

3 Phase fight, each 33% ticks over to the next phase.

First off the the Permafrost (not the Anub one), which does the whole frost damage but stacks increasing magic damage taken.  But it is LoS'able.

Second is the Saronite Boulders he throws out, will knock people back if they stand under it.   Also creates LoS objects.

So those 2 above combined, is kinda like Sindragosa practice.  Use the boulders to LoS him to drop off your debuffs.

Phase 2 appears to just mean you don't wanna stand in front of him when he casts Chilling Wave (and more frost damage around)

Phase 3 appears to just mean healers might want to watch deep freeze target, and it'd be tougher to get LoS to drop the debuffs (and even more frost damage around).

Tanks should use the Phase transitions to try to drop off the debuff.

Ick and Krick:

• Toxic Waste - Deals Nature damage to all enemies within the acid. Lasts 10 sec. Instant. Ticks for 25% of total health every 2 seconds.
• Mighty Kick - Inflicts 150% Weapon Damage to an enemy, knocking it back
• Shadow Bolt - Hurls a bolt of dark magic at an enemy, inflicting Shadow damage. 2125-2900 damage.
• Pursuit - The super zombie fixates on a random target. 5 sec cast. Debuff on the fixated player. Lasts 12 seconds
• Pursuit Confusion - Confused by the change in orders, the zombie moves more slowly. Instant. Buff on Ick. -50% movement speed. +50/100% damage. Immune to taunts. Lasts 12 seconds.
• Poison Nova - Gushes a massive volley of poison, harming all nearby enemies. Lasts 21 sec. 5
  second cast. One big explosion for 12/30k damage. Anyone hit will also
  take 1500/6500 damage every 3 seconds for 21 seconds after that.
• Explosive Barrage - Launches explosive missiles at every nearby target. 2 sec cast. Lasts 18 seconds
• Explosive Barrage - Launches a barrage of explosive orbs at all enemies. Explosive orbs deal 3000 Arcane damage when they detonate. Instant. 6000 damage on Heroic. Cast by the exploding orbs summoned at players' positions.

Tank and spank and move.   Krick will just be the gnome on Ick's shoulders giving orders.   Kill Ick.

First off, poison pools are dropped, so move away.

Second trick is a Poison Nova that hurts.   Run away, 18 yards when casting, you have 5 seconds.

He'll also target someone at some point and chase em, you can run and kite.

There's also bombs, exploding kinds, keep moving away from them.

Scourgelord Tyrannus:

• Forceful Smash - Knocks an enemy back with a powerful blow, inflicting 28275 to 31725 Physical Damage Instant. 47125-52875 on Heroic (10 sec cooldown)
• Overlord's Brand
  - 1.5 seconds cast. Debuff randomly cast on party members. If the
  afflicted player is a damage dealer, all damage dealt is redirected to
  the tank. If the person is a healer, all healing heals Tyrannus
  instead. Lasts 8 seconds. Cannot be dispelled.
• Unholy Power - Empowers the caster with dark might, increasing physical damage by 75% but reducing movement speed by 50% for 10 sec. 0.75 sec cast. Lasts 10 seconds. Heroic: +100% damage. No speed reduction

Rimefang

• Mark of Rimefang - issued by Tyrannus; marks a target to be attacked by Rimefang for 7 seconds.
• Hoarfrost - Deals 4813 to 6187 Frost damage to enemies within 8 yards of the point of impact and stuns them for 5 sec. 5 sec cast. Cast on the player with the Mark of Rimefang. 7875-10125 on Heroic
• Icy Blast - Deals 4813 to 6187 Frost damage to enemies within 7 yards of the point of impact. Instant. Cast whenever Rimefang is not casting Hoarfrost. 6563-8437 on Heroic
• Icy Blast - Reduces movement speed by 75% and inflicts 2313 to 2687 Frost damage per 2 sec. on those caught within the lingering icy chill. Cast by the Icy Blast areas on the ground after Rimefang's Icy Blast attack. Ticks every second on Heroic

Lots of damage, keep the tanks topped off whenever possible

Rimefang is his frostwyrm mount that flies around attacking us.  Though his attacks are avoidable Ice attacks if you keep moving away from where he's shooting it.

During Unholy Power, it's like Vezax, kite him around.  You can use the frost patches Rimefang leaves behind.   Or eventually, take the hits if you're overgeared for this fight.

Also watch for the Brand debuff, dps will be killing your tank, and healers will be healing him if you get it.  Stop for 8 seconds when you have it.

Trash:

Corrupted Champion 

 Skeleton. Raised from Coliseum Champion by Scourgelord Tyrannus. Killed by the faction hero defending herself.

Deathwhisper Necrolyte

 Necromancer. Leads a group of Skeletal Slaves.  Casts Shadow Bolts and Conversion Beam.

Skeletal Slave
 Skeleton.  Group of six non-elites.

Wrathbone Laborer
 Bone giant.  Solo pulls. Casts Shovelled! on melee and Blinding Dirt on ranged

Deathwhisper Shadowcaster 
 Undead. In four-pulls with a torturer and two ghouls. Shadow Bolt and Seed of Corruption

Deathwhisper Torturer

 Undead.  In four-pulls with a shadowcaster and two ghouls. Curse of Agony and Black Brand: +50% incoming shadow damage for 10 sec

Hungering Ghoul
 Ghoul.  In four-pulls with a shadowcaster and a torturer. Devour Flesh: ~2k health/5% stamina transferred to ghoul for 15 sec

Ymirjar Skycaller
 Vrykul. Mounted astride Iceborn Proto-Drakes.   Glacial Strike: 15% damage/3 sec until fully healed. Summons a Whirlwinding Frostblade

Iceborn Proto-Drake

 Proto-drake.  Ridden by a skycaller until aggro. Frost Breath.

Plagueborn Horror

 Plague eruptor.  Solo pulls near Krick/Ick. Toxic Waste patches, Pustulant Flesh debuffs and a kamikaze Blight Bomb near death

Geist Ambusher

Geist. Four or five ambush the rescued slaves along the path between the forgemaster and Krick with Leaping Face Smash

Stonespine Gargoyle

Gargoyle. Cannot be attacked until they drag and drop slaves of the other faction.

Ymirjar Flamebearer

Ymirjar. Summoned by the deathbringer after Krick. Fireball, Tactical Blink (Shadowstep) and Hellfire

Ymirjar Deathbringer

Vrykul. Summons two flamebearrers and a wrathbringer after Krick. Empowered Shadowbolt: hitting two for the price of one

Ymirjar Wrathbringer

Ymirjar. Summoned by the deathbringer after Krick. Blight:
Disease. 2k damage per 3 sec for 15; if not cleansed, bounces to
another player

Fallen Warrior

Skeletal warrior. After the first two big pulls, groups of two
are in the gauntlet. Demoralizing Shout. Shield Block. Arcing Slice
(Sunder Armor)

Wrathbone Coldwraith

Skeletal mage. In big pulls before the gauntlet with the fallen warriors. Frostbolt. Freezing Circle.

Wrathbone Skeleton

Skeleton. In the gauntlet. Two weak elites summoned every 30 seconds or so running toward the entrance.

Disturbed Glacial Revenant

Revenant. Heroic mode only. Halfway through the gauntlet.