Encounter Details

Thorim

• HP: 19.5 million (Heroic) / ?? million (Normal)
• Touch of Dominion - If you don't reach Thorim within the Hard Mode timer, he receives the debuff called Touch of Dominion that reduces his HP and damage by 25%.
• Abilities
  • Lightning Charge - Absorbs a torrent of electrical energy, inflicting Nature damage to enemies in a cone between the caster and the power source, and increasing the caster's melee damage and attack speed by 15%, and Nature damage dealt by 10%. (Stacks 99 times)
    
    • Secondary effect: Lightning Charge - Absorbs a torrent of electrical energy, inflicting 13875 to 16125 Nature damage to enemies in a cone between the caster and the power source.
  • Unbalancing Strike - Inflicts 200% weapon damage and leaves the target unbalanced, reducing their defense skill by 200 for 15 sec.
  • Thorim spawns bubbles that stun you if they get too close.  They can be avoided.
  • Chain Lightning - Strikes an enemy with a blast of lightning that inflicts 3700 to 4300 Nature damage. The bolt will arc to additional nearby enemies, inflicting 100% more Nature damage to each successive target.
• Hard Mode
  • If you get to Thorim within 3 minutes, Sif doesn't despawn and she assists him in the fight.
  • Sif
    • Abilities
      • Blizzard - A rain of ice moves around the room, dealing 3282 to 4218 Frost damage every 1 sec. for 10 sec. (10 player: 2188 to 2812 Frost damage)
      • Frostbolt Volley - Inflicts 9000 to 11000 Frost damage to nearby enemies, reducing their movement speed for 4 sec. (10 player: 7200 to 8800 damage)
      • Frost Nova - Inflicts 9425 to 10575 Frost damage to nearby enemies, immobilizing them for up to 6 sec. (10 player: 7069 to 7931 Frost damage)

Trash Event

This encounter starts off with a trash event.  The first thing you'll see is a Jormungar Behemoth fighting captured soldiers of the opposite faction (Horde if you're Alliance, Alliance if you're Horde).  The captured soldiers aren't friendly to you, so you'll have to deal with the damage they deal as well as the Jormungar and any adds that spawn during the event.

• Trash HP: 2.3 to 2.5 million (Heroic)
• During the trash event, the following abilities are used by Thorim.
• Don't bother attacking Thorim during this phase; he's protected by Shealth of Lightning which reduces his damage taken by 99%.
• Stormhammer - Throws a stormhammer, dealing 2451 to 2551 damage to an enemy, knocking down and stunning the target for 2 sec, and causing a deafening thunderclap to all enemies nearby the target.
  • Deafening Thunder - Inflicts 4625 to 5375 Nature damage to enemies standing in close proximity to a Stormhammer strike, increasing spell casting times by 75% for 8 sec.
  • Thorim throws this at targets during the trash event phase.
• Berserk - Damage done increased by 500%. Attack and cast speed increased by 200%. Health increased by 300%.
  • Thorim casts this on the adds during the trash event if you take longer than 5 minutes to get to him.
    

Jormungar Behemoth Phase

• Abilities
  • Acid Breath - Spews acidic bile at a target and nearby enemies, inflicting 12000 Nature damage and 1500 additional damage every 2 sec. for 18 sec. (10 player: 6000 Nature damage)
  • Sweep - Sweeps at the legs of an enemy, dealing 6000 damage and causing knockdown for 3 sec. (10 player: 3500 damage)
• Thunder Orb
  • Charge Orb - Charges a nearby orb with electricity. Firing static bolts every 1 sec. for 15 seconds.
    • Lightning Shock - Inflicts 2831 to 3169 Nature damage on a nearby enemy.
• Captured Mercenary Captain
  • Devastate - Sunder the target's armor causing the Sunder Armor effect.  In addition, causes 50% of weapon damage plus 90 for each application of Sunder Armor on the target.  The Sunder Armor effect can stack up to 5 times.
  • Heroic Strike - A strong attack that deals 3938 to 5062 additional Physical damage. (Plus weapon damage)
    
• Captured Mercenary Soldier
  • Barbed Shot - Fires an arrow that pierces an enemy's flesh, inflicting 4513 to 4987 Physical damage and causing 500 damage per 3 sec. for 12 sec.
  • Wing Clip - Inflicts 20% normal melee damage and reduces the enemy target's movement speed by 30% for 10 sec.

Construct Phase

After you complete the Jormungar Behemoth event you have to deal with these adds in the arena, as well as the second set of adds below through the gate in the hallway.

• Unknown - The source of these two abilities is unknown, but they occur during the construct phase of the event.
  • Aura of Celerity - Increases nearby allies' melee, ranged, and casting speed by 20%.
  • Runic Fortification - Damage done increased by 50%. Attack and cast speed increased by 50%. Health increased by 100%.
• Dark Rune Commoner
  • Low Blow - Lands a cheap shot on an enemy, inflicting Physical damage and reducing the target's damage dealt by 3% for 20 sec. (Stacks to 25)
• Dark Rune Evoker
  • Runic Lightning - Strikes an enemy with a blast of runic lightning, inflicting 7875 to 10125 Nature damage. (10 player: 6563 to 8437 Nature damage)
  • Runic Mending - Heals an ally for 18500 to 21500, then heals for an additional 6000 every 1 sec. for 15 sec. (10 player: 11563 to 13437 heal, additional 4000 every 1 sec.)
  • Runic Shield - Surrounds the caster with a runic barrier, absorbing 120000 magical damage and reducing all Physical damage taken by 50%. (Can be dispelled)
• Dark Rune Warbringer
  • Runic Strike - Strikes at an enemy with an electrified weapon, inflicting Nature damage equal to weapon damage plus 1000.
• Dark Rune Champion
  • Whirlwind - Attacks nearby enemies in a whirlwind of steel that lasts 2 sec. and inflicts normal damage plus 50.
  • Mortal Strike - Inflicts 250% weapon damage and leaves the target wounded, reducing the effectiveness of any healing by 50% for 5 sec.
  • Charge - Charges an enemy, inflicting normal damage plus 75 and stuns the opponent for 2 sec.
• Dark Rune Acolyte
  • Greater Heal - Heals for 94500 to 115500.
  • Renew - Heals a friendly target for 13650 to 14350 per 3 sec. for 15 sec.
  • Holy Smite - Smites an enemy, inflicting 7650 to 9350 Holy damage.
• Iron Honor Guard
  • Cleave - Inflicts 150% of normal melee damage to an enemy and its nearest ally.
  • Shield Smash - Inflicts 7400 to 8600 Physical damage to an enemy, stunning it for 3 sec.
  • Hamstring - Inflicts 50% weapon damage to an enemy, reducing its movement speed by 60% for 5 sec.
• Titanium Stormlord
  • Cyclone - Attacks nearby enemies in a whirlwind that inflicts Nature damage. (100% weapon damage)

While the group in the arena kills off any adds that attack, you must also clear through the hallway to reach Thorim to trigger his phase of the fight.

• Trash Pack - These roam together in a pack in the hallway to Thorim during the event.
  • Dark Rune Thunderer
    • Lightning Brand - Shocks the target for 3500 Nature damage to the target, and increases Nature damage taken by 40% for 20 sec. (Stacks to 99)
  • Iron Ring Guard
    • Impale - Deals a vicious attack that causes the target to bleed profusely until healed past 90% of its maximum health.  Deals 1750 damage every 2 sec. for 1 min or until removed via healing.
    • Ravage Armor - Reduces the target's armor by 5%. (Stacks to 20)
    • Whirling Trip - Knocks down nearby enemies, stunning them for 2 sec. and inflicting increased weapon damage.
• Mini-boss #1: Runic Colossus
  • HP: ~810k (Heroic)
  • Charge - Charges an enemy, inflicting 6938 to 8062 Physical damage and knocking the enemy back.
  • Runic Barrier - A shield of runic power surrounds the caster, reducing Physical damage taken by 50% and inflicting 2000 Arcane damage to attackers.
  • Smash - Deals 37000 to 43000 Physical damage to all enemies within a 10 yard cone in front of the caster.
• Mini-boss #2: Ancient Rune Giant
  • HP: ~1 million (Heroic)
  • Rune Detonation - Immobilizes a target with a runic ward that detonates after 4 sec to inflict 11250 to 13750 Fire damage around the target.
  • Stomp - Inflicts 12250 to 15750 Physical damage to nearby enemies and knocks them back.

Video

Now that you've read up on the encounter, take a moment and watch this video to see things in action.

25-player Loot

Items are sorted by slot: Weapons, Armor, and then everything else.

Hard Mode

Normal Mode

10-player Loot

Items are sorted by slot: Weapons, Armor, and then everything else.

Normal Mode

Achievements

25-player
Achievement	Rewards
Meta: Conqueror of Ulduar Defeat each boss in Ulduar on Heroic Difficulty without allowing any raid member to die to that boss at any point during that raid lockout period.	10 "Conqueror of Ulduar"
Meta: Heroic: Glory of the Ulduar Raider Complete the Heroic Difficulty raid achievements listed below.	25 Ironbound Proto-Drake
Meta: Heroic: The Keepers of Ulduar Defeat the Keeper bosses of Ulduar on Heroic Difficulty.	10
Heroic: Don't Stand in the Lightning Defeat Thorim without any raid member being struck by Lightning Charge on Heroic Difficulty.	10
Heroic: I'll Take You All On Defeat Thorim, the Ancient Rune Giant and the Rune Colossus on Heroic Difficulty.	10
Heroic: Lose Your Illusion Defeat Thorim while Sif is present on Heroic Difficulty.	10
Heroic: Siffed Force Thorim to enter the arena while Sif is present on Heroic Difficulty.	10
Heroic: Who Needs Bloodlust? Defeat Thorim while under the effect of Aura of Celerity on Heroic Difficulty.	10
10-player
Achievement	Rewards
Meta: Champion of Ulduar Defeat each boss in Ulduar on Normal Difficulty without allowing any raid member to die to that boss at any point during that raid lockout period.	10 "Champion of Ulduar"
Meta: Glory of the Ulduar Raider Complete the Normal Difficulty raid achievements listed below.	25 Rusted Proto-Drake
Meta: The Keepers of Ulduar Defeat the Keeper bosses of Ulduar on Normal Difficulty.	10
Don't Stand in the Lightning Defeat Thorim without any raid member being struck by Lightning Charge on Normal Difficulty.	10
I'll Take You All On Defeat Thorim, the Ancient Rune Giant and the Rune Colossus on Normal Difficulty.	10
Lose Your Illusion Defeat Thorim while Sif is present on Normal Difficulty.	10
Siffed Force Thorim to enter the arena while Sif is present on Normal Difficulty.	10
Who Needs Bloodlust? Defeat Thorim while under the effect of Aura of Celerity on Normal Difficulty.	10