For character biography, see Thorim.
Image of Thorim
Gender Male
Race Titanic watcher (Giant)
Level ?? Boss
Resource Mana
Reaction Alliance Horde
Location The Clash of Thunder
Status Defeatable

Thorim is one of the watchers boss encounters in Ulduar. The encounter has two phases, in the first, the raid has to split in a gauntlet and an arena team. The arena team must fight waves of adds while the gauntlet team makes its way through some trash and a few mini-bosses to Thorim. Upon reaching the boss, he and the gauntlet group join the arena team, starting the second phase which lasts until Thorim is subdued.

Both, fire and nature resistance are useful. When attempting hard mode, a little frost resistance gear is recommended.



For many years Thorim believed that the ice giants had murdered his beloved wife, Sif, not realizing that his brother, Loken, was truly responsible. When Thorim learned the truth, Loken ensnared him and brought him to Ulduar.[1]

Adventure Guide

For years, Thorim believed that ice giants had murdered his beloved wife Sif. Thorim turned his wrath upon his allies and fell into despair. When he learned that his brother Loken was responsible for the crime, Loken captured Thorim and brought him to Ulduar, where the Old God clouded the keeper's mind.


Thorim calls in Dark Rune forces to engage players that are in the Arena until allies are able to reach Thorim by traveling through the Hallway. Once players reach Thorim he will leap into the arena and use powerful Lightning attacks to defeat his foes.

Dps icon.png Damage Dealers

  • While in the Arena interrupt the Dark Rune Acolyte's Greater Heal and the Runic Mending cast by Dark Rune Evokers.
  • Avoid Thorim's Lightning Charge once Stage Two begins.
  • While in the Hallway avoid Runic Smash cast by the Runic Colossus.

Healer icon.png Healers

  • Avoid Thorim's Lightning Charge once Stage Two begins.

Tank icon.png Tanks

  • Avoid Thorim's Lightning Charge once Stage Two begins.
  • While in the Hallway avoid Runic Smash cast by the Runic Colossus.
  • While in the Hallway avoid Smash cast by the Runic Colossus once it is engaged.
  • Take turns tanking Thorim to manage Unbalancing Strike.


Stage One: Prove Your Worth

Thorim calls in Dark Rune forces to engage players that are in the Arena until allies are able to reach Thorim by traveling through the Hallway.

  • Thorim
    • Inv hammer 01.png  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.
    • Spell nature thunderclap.png  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.
    • Spell nature chainlightning.png  Charge Orb — Charges a nearby orb with electricity.
  • The Arena
    • Dark Rune Acolyte
      • Spell holy renew.png  Renew Magic Effect — Heals a friendly target for 13650 to 14350 per 3 sec. for 15 sec.
      • Spell holy flashheal.png  Greater Heal Interruptible — Calls upon Holy magic to heal an ally.
      • Spell holy holysmite.png  Holy Smite Interruptible — Smites an enemy, inflicting 7650 to 9350 Holy damage.
    • Dark Rune Champion
      • Ability warrior savageblow.png  Mortal Strike — Inflicts 250% weapon damage and leaves the target wounded, reducing the effectiveness of any healing by 50% for 5 sec.
      • Ability whirlwind.png  Whirlwind — Attacks nearby enemies in a whirlwind of steel that lasts 2 sec. and inflicts additional damage.
      • Ability warrior charge.png  Charge — Charges an enemy, inflicting damage and stunning the opponent for 2 sec.
    • Dark Rune Commoner
      • Inv gauntlets 04.png  Pummel — Pummels an enemy interrupting the spell being cast for 5 sec.
      • Ability rogue kidneyshot.png  Low Blow — Lands a cheap shot on an enemy, inflicting Physical damage and reducing the target's damage dealt by 3% for 20 sec.
    • Dark Rune Evoker
      • Spell nature chainlightning.png  Runic Lightning Interruptible — Strikes an enemy with a blast of runic lightning, inflicting 7875 to 10125 Nature damage.
      • Spell arcane manatap.png  Runic Mending Interruptible Magic Effect — Heals an ally for 18500 to 21500, then heals for an additional 6000 every 1 sec. for 15 sec.
      • Spell holy blessedresillience.png  Runic Shield Magic Effect — Surrounds the caster with a runic barrier, absorbing 120000 magical damage and reducing all Physical damage taken by 50%.
    • Dark Rune Warbringer
      • Spell arcane arcaneresilience.png  Aura of Celerity Important — Increases nearby allies' melee, ranged, and casting speed by 20%.
      • Inv sword 05.png  Runic Strike — Strikes at an enemy with an electrified weapon, inflicting Nature damage equal to weapon damage plus 1000.
  • The Hallway
    • Iron Ring Guard
      • Ability backstab.png  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.
      • Inv spear 05.png  Whirling Trip — Attacks the target with a spinning strike, knocking down and stunning them for 2 sec and inflicting increased weapon damage.
    • Dark Rune Acolyte
      • Spell holy renew.png  Renew Magic Effect — Heals a friendly target for 13650 to 14350 per 3 sec. for 15 sec.
      • Spell holy flashheal.png  Greater Heal Interruptible — Calls upon Holy magic to heal an ally.
      • Spell holy holysmite.png  Holy Smite Interruptible — Smites an enemy, inflicting 7650 to 9350 Holy damage.
    • Runic Colossus
      • Spell fire sealoffire.png  Runic Smash — Deals 9425 to 10575 Fire damage to nearby enemies.
      • Ability warrior cleave.png  Smash Tank Alert — Deals 37000 to 43000 Physical damage to all enemies within a 10 yard cone in front of the caster.
      • Spell arcane prismaticcloak.png  Runic Barrier Tank Alert — A shield of runic power surrounds the caster, reducing all damage taken by 50% and inflicting 2000 Arcane damage to attackers.
      • Ability warrior charge.png  Charge Tank Alert — Charges an enemy, inflicting 4625 to 5375 Physical damage and knocking the enemy back.
    • Iron Honor Guard
      • Ability shockwave.png  Hamstring — Inflicts 50% weapon damage to an enemy, reducing its movement speed by 60% for 5 sec.
      • Ability warrior shieldbash.png  Shield Smash — Inflicts 7400 to 8600 Physical damage to an enemy, stunning it for 3 sec.
      • Ability warrior cleave.png  Cleave — Inflicts 150% of normal melee damage to an enemy and its nearest ally.
    • Ancient Rune Giant
      • Trade engraving.png  Runic Fortification — Fortifies nearby allies.
      • Ability warstomp.png  Stomp — Inflicts 8313 to 10687 Physical damage to nearby enemies and knocks them back.
      • Spell fire sealoffire.png  Rune Detonation — Immobilizes a target with a runic ward that detonates after 4 sec to inflict 11250 to 13750 Fire damage around the target.

Stage Two: Keeper of Storms

  • Thorim
    • Spell nature chainlightning.png  Chain Lightning — Strikes an enemy with a blast of lightning that inflicts 10725 to 11275 Nature damage. The bolt will arc to additional nearby enemies, inflicting 100% more Nature damage to each successive target.
    • Spell lightning lightningbolt01.png  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%.
    • Ability warrior decisivestrike.png  Unbalancing Strike Tank Alert — Inflicts 200% weapon damage and leaves the target unbalanced, increasing damage taken by 50%.

Hard Mode

If players traverse the Hallway quick enough and reach Thorim within 90 seconds Sif will join the battle in Stage Two.

  • Sif
    • Spell frost frostbolt02.png  Frostbolt Volley — Inflicts Frost damage to nearby enemies, reducing their movement speed for 4 sec.
    • Spell frost frostnova.png  Frost Nova Magic Effect — Inflicts 7069 to 7931 Frost damage to nearby enemies, immobilizing them for up to 6 sec.
    • Spell frost icestorm.png  Blizzard — A rain of ice moves around the room, dealing 2188 to 2812 Frost damage every 1 sec. for 10 sec.


Phase 1

The fight is started by killing the trash mobs in the Arena (healer first). Thorim casts Sheath of Lightning on himself, making him almost invulnerable. After the mobs are down, the lever next to the gate on the left becomes active. The raid should now split in two, one part goes down the hallway to reach Thorim, and the other part stays in the arena to fight waves of adds.

The Gauntlet

The gauntlet team needs one tank and one healer. In 10 player mode, 1-3 damage dealers suffice, in 25 player mode an extra healer and about 7 damage dealers should be sent. Ranged DPS is better suited for the gauntlet, mages in particular. The gauntlet team must move quickly, because after 5 minutes Thorim wipes the raid.

There are 3 groups of 3 Warbringers. They can be Crowd Controlled, ( [Polymorph] in particular). Two mobs should be CC'd while the others are killed. At the end of the hallway is a large golem. In regular intervals it raises one arm and does damage to anyone on that side of the hallway, much like Skadi. A short time after it is engaged it gains a buff which decreases damage taken by 50%, so if using cooldowns it's best to use them early.

After defeating the golem, the door behind it opens and mobs start spawning on top of the stairs. Defeat or CC the two sets of two mobs already standing there and quickly run up. When the giant aggros, he buffs any adds still alive, but the adds stop spawning. The healers must have LOS to the tank but stand outside the giant's stomp. When the giant is positioned at the top of the stairs, the healer can stand about halfway down.

After the giant is defeated the gauntlet team runs towards Thorim and jumps down into the arena. Someone must use any ability on Thorim to make him join. While running the large circles on the ground must be avoided, they are traps which briefly stun players standing on them.


The raid members positioned closest to Thorim gain initial aggro from all spawned adds.

A simple setup for the arena team is to stack up dead center in the room. This avoids getting hit by the charged orbs, and also greatly increases the effects of both, AoE healing and AoE damage. The disadvantage of this method is that it makes the raid more susceptible to Stormhammer - it's possible to just take Stormhammer, but the group can also try to quickly spread out when it hits.

The most dangerous mobs are the Dark Rune Champions which do a whirlwind atteck. They need to be kept away from the main raid, and/or disarmed. The Evokers casts heals-over-time that heal for massive amounts and also cast magic damage shield that can be stolen by mages. Both are dispellable and need to be dispelled/stolen quickly. Wound poison helps to reduce the amount healed.

Phase 2

Once Thorim is activated, he jumps down into the Arena. The mob waves stop spawning. During the whole of Phase 2, Thorim gains an extra Lightning Charged buff every 10 seconds. This buff stack progressively increases damage and attack speed, it's in effect a passive enrage timer. From about 7 stacks on, healers and tanks need to use some CDs to survive, after about 15 buffs Thorims melee hits can one-shot even the best geared tank.

After Thorim is in the arena, he needs to be picked up by the MT immediately. The raid should spread out to avoid extra damage from Thorims' chain lightning. Every time Thorim uses Unbalancing strike (which is every 15–20 seconds), tanks need to taunt him off each other. When Thorim uses Lightning Charge, small lightning balls come from a column. After a short time, that column deals large amounts of AoE damage in a 60 degrees angle, this damage may be enough to one-shot players after the third Lightning Charge.

Hard mode: Lose your Illusion

The illusion of Sif controlling Thorim

If the gauntlet team reaches Thorim within 2:45 min (6:15 on Heroic) of killing the adds in the entrance, the illusion of Thorim's wife Sif joins the fight. Additionally, Thorim gets +43% health and +67% damage compared to Normal Mode (it is not only +30%/+40%, since the debuff Touch of Dominion being applied for Normal Mode reduces his stats by -30%/-40% from the Hard Mode values).

While the increased damage is not a large deal, the additional HP make the fight longer, which means a substantially higher stack of Lightning Charged.

In hard mode, Thorim's Chain lightning is very dangerous to melee, so it is advisable to form 2-3 melee camps more than 8 yards from each other around the boss, as with Kel'Thuzad at 60.

Raid Positioning

Sif herself is unattackable. She has four abilities which when chained together can kill raid members very quickly.

  • Frostbolt Single: This does 11,000-13,000 Frost damage and is chain cast on random targets when Sif isn't casting anything else.
  • Frostbolt Volley: This is the same damage as her single target frostbolt and hits everyone in the room every 10–15 seconds.
  • Frost Nova: Sif frequently teleports to a random location starts a 2.5 sec cast of Frost Nova. It does high amounts of damage (13,000-15,000) so avoiding it by running away is paramount but not always possible due to the snares.
  • Blizzard: Much like Shade of Aran, Sif conjures a Blizzard which orbits the perimeter of the room, making the center area 'safe'. It does 4,500 Frost damage every 2 seconds and snares targets by 50%.

When Thorim is defeated 'Sif' reveals itself for what it is: an influence tentacle of Yogg-Saron.


Demoralizing Shout cuts the damage the tank receives from unbalancing strike by 40%.

Priests can MC a Dark Rune Warbringer. Besides dealing high damage, they also give all nearby allies a permanent buff called "Aura of Celerity", increasing melee, ranged and spell haste by 20%, practically a permanent [Bloodlust] (also requirement for the achievement  Who Needs Bloodlust? (10 player) /  Who Needs Bloodlust? (25 player)). In addition, the mind-controlled Warbringers hit harder than most level 80 players.


Main article: Cache of Storms (Ulduar)
Cache of Storms

Related achievements

Hard mode

The following achievements are for the encounter's hard mode:


Thorim yells: Interlopers! You mortals who dare to interfere with my sport will pay... Wait--you...
Thorim yells: I remember you... In the mountains... But you... what is this? Where am--
Sif yells: Thorim, my lord, why else would these invaders have come into your sanctum but to slay you? They must be stopped!
  • Behold the power of the storms and despair!
  • Do not hold back! Destroy them!
  • Have you begun to regret your intrusion?
Missed Hard Mode
Sif yells: These pathetic mortals are harmless, beneath my station. Dispose of them!
Thorim jumps down
Impertinent whelps, you dare challenge me atop my pedestal? I will crush you myself!
Hard Mode Reached
Sif yells: Impossible! Lord Thorim, I will bring your foes a frigid death!
Killing a player
  • Can't you at least put up a fight!?
  • Pathetic!
Wipe in Arena
Failures! Weaklings!
My patience has reached its limit!
Stay your arms! I yield!
Outro on Normal Mode
I feel as though I am awakening from a nightmare, but the shadows in this place yet linger.
Sif... was Sif here? Impossible--she died by my brother's hand. A dark nightmare indeed....
I need time to reflect.... I will aid your cause if you should require it. I owe you at least that much. Farewell.
Outro on Hard Mode
You! Fiend, you are not my beloved! Begone!
Behold the hand behind all the evil that has befallen Ulduar, left my kingdom in ruins, corrupted my brother, and slain my wife.
And now it falls to you, champions, to avenge us all. The task before you is great, but I will lend you my aid as I am able. You must prevail.
Buffing for Yogg-Saron's encounter

Mortals, I am indebted to you for freeing me from the terrible corruption that besets this place. Though I have not yet recovered fully, I can help you battle Yogg-Saron.

I can grant you and your friends the Fury of the Storm, increasing your damage and maximum health. Should you be face with evil so malevolent that it cannot be destroyed, I can channel all my power into a final Titanic Storm that will destroy even Immortals.

Gossip Lend us your aid, keeper. Together we will defeat Yogg-Saron.

Golganneth, lend me your strengh! Grant my mortal allies the power of thunder!

Sound files

See Sound Files of Ulduar: Thorim


10-man encounter

25-man encounter

25-man Hard mode encounter

Patches and hotfixes


External links