Thorim - Ulduar boss guide

Tactics for Thorim, Guardian of Ulduar 10/25 for WoW 3.3.5a: arena and corridor, Storm Hammer, Unbalancing Strike, Chain Lightning, Lightning Bolt, hardmode with Sif and full loot.
Review
Thorim - Guardian of Ulduar, god of thunder, enslaved by Yogg-Saron through the illusion of his murdered wife Sif. Mandatory boss from the Guardian block. The battle is divided in two: first, the raid is divided into two groups - one cuts down waves of enemies in the arena, the second makes its way along the corridor to Thorim's throne, where he watches from above and is invulnerable (Lightning Shell). As soon as the corridor group reaches Thorim, he jumps into the arena - the second phase begins, a classic battle in the center of the hall. Hardmode is all about speed: if you get to Thorim while Sif is still casting Touch of Power (150 sec in the script, ~2.5 minutes), she stays and helps him with frost spells, and Thorim himself receives +25% HP and damage. Thorim is not killed: at ~1% he surrenders.
- Divide the raid: arena - almost all miles + tank + 2 heals; corridor - range + tank + a couple of healers (there are a lot of mobs in the corridor that are deadly for miles).
- Hardmode: get to Thorim while Sif is casting Touch of Power (~2.5 minutes). We succeeded - Sif remains, Thorim +25% HP/damage. If you don’t want hardmode, wait until the end of her cast and only then beat Thorim.
- In the arena, focus Dark Rune Casters (heal/shield) first, then Dark Rune Champions (AoE damage). The Prior can use Mass Dispersal to disrupt their healing and shields.
- In the corridor near the Runic Colossus: the raid shifts to the half where the Powerful Rune Strike does NOT hit (look at his hands), and after aggro stands behind him (he has Charge and Runic Barrier-Reflector - kills fast attackers).
- For the Ancient Rune Giant: the tank has its back to the wall (Stomp spreads), the raid diverges from the target of the Rune Explosion. IMPORTANT: Rune Explosion's dispel makes it work INSTANTLY - don't dispel blindly.
- Phase 2: miles in 2-3 groups around the boss, range scattered - Chain Lightning (62131) hits +100% for each jump and in late stacks one-shots after 2 jumps.
- Unbalancing Strike (62130) removes 200 defense for 15 sec - the tank becomes vulnerable to crits and crushing blows. Tank swap immediately, the blow cannot be dodged/parried/blocked (but you can miss).
Combat phases
The raid is divided in two. ARENA: first Jormungar the Behemoth + enemy NPCs, then endless waves of rune dwarves (champions, spellcasters, warriors, commoners). Thorim hits the arena from aboveStorm Hammer and charges the pillars with a Charged Ball. CORRIDOR: the second group makes its way past the Rune Colossus (spawns mobs + Powerful Rune Strike along half of the corridor) and the Ancient Rune Giant (Stomp, Rune Explosion), then along the mined area along the walls to Thorim. The first blow to Torim throws him into the arena.
- Divorce into 2 groups
- Arena: Spellcaster Focus → Champions
- Hallway: Dodging Rune Slam
- Don't Step on Traps - Paralysis
- Speed decides hardmode
Thorim jumps down and fights in the center.Unbalancing Strike every ~8 sec on a tank,Chain Lightning every ~13 sec, and it periodically charges the pillar → Lightning bolt in a cone in an area in front of the pillar + Torimu stack of Lightning bolt (+15% melee/+10% nature). Stacks - soft enrage; plus hardBerserk at the 5th minute.
- Miles in 2-3 groups, scattered range
- Tank swap byUnbalancing Impact
- Moving away from the lightning discharge cone from the pillars
- Race with stacks up toBerserker
After interrupting Sif's cast, you turn on hard mode: Thorim +25% HP and damage, and Sif descends and until the end of the battle fires at the raid with Ice Arrows, a Volley of Ice Arrows, Blizzard and Immobilizes with Ring of Cold. You can't kill her. Deadly combo: Ice Arrow +Chain Lightning/Lightning Bolt, or Ring of cold directly under the pillar cone.
- All burst CDs at once on the debuffed Thorim
- Save immunities/protections for late stacks
- Do not stand in the pillar cone under the Ring of Cold
- The snowstorm is driven towards the center
Abilities
Positioning
Phase 1: two sites. Arena - the tank collects waves with its muzzle from the raid, miles and some of the heals are clustered, range and heals scatter from the Storm Hammer; whoever is closest to Thorim's throne will be the first to be aggrated by adds - healers should not run ahead of the tank. The corridor is a compact column, displaced by the powerful blow of the rune, and stands at the edges of the giants. Phase 2: Torim in the center, miles in 2-3 groups, range in a wide ring around the perimeter, away from the pillars.
Role Tips
- Unbalancing Strike you can’t block/parry/dodge - you can only miss; swap is immediate, don't wait.
- In the corridor, place the Ancient Rune Giant with its back to the wall, otherwise the Stomp will scatter you and the raid.
- At the Rune Colossus, stand in a raid behind him - this way he will not Charge into the distant ones.
- A paladin tank with a block cap removes 8-10% of Thorim's white damage - this is huge on accelerating hits.
- Stacks of Lightning Bolt constantly raise all Thorim's damage - plan for the CD on 7+ stacks rather than reacting after the fact.
- VictimStorm Hammer Heal up in the arena: stun + damage is dangerous under adds.
- In hardmode, keep a dispel ready: Sif's Ring of Cold under the cone of the pillar = death without removal.
- Prior's mass dispel removes Runic Healing and Runic Shield from arena adds - spellcasters stop saving them.
- Hardmode - corridor race: fight your way without stopping to catch the end of Sif's cast (~2.5 minutes).
- If you don't want hardmode, wait until the end of Touch of Power, only then beat Thorim.
- Phase 2: range strictly scattered -Chain lightning+100% for jumping and one-shots on stacks.
- Dispell the Explosion rune in the corridor detonates it instantly - do not remove it near the raid.
- Save immunities (Ice Block, Cloak of Shadows, Divine Shield) for late stacks - Lightning Bolt is an almost guaranteed one-shot.
Loot
| Slot | Item | Classes | Note |
|---|---|---|---|
| Head | Form of the Midgard Serpent | RogueDruid | 10. Skin, physical dps: 107 agility, 82 stamina, crit, 155 AP, mastery, meta + blue socket. |
| Weapons | Legacy of Thunder | WarriorPaladinDruidDeath Knight | 10. One-handed blunt weapon 1.70, tank: 37 strength, 73 stamina, defense, evasion, mastery, 1612 AP in beast form. |
| Hands | Gloves of Resonance | PriestMageWarlock | 10. Fabric, heal/caster: 62 stamina, 63 int, 56 spirit, 55 crit, 105 SP. |
| Belt | Blood Cauldron Belt | HunterShaman | 10. Chain mail, physical dps: 56 agility, 71 stamina, 48 int, haste, 167 AP, ArP. |
| Legs | Flash Leggings | PriestMageWarlock | 10. Fabric, DPS caster: 113 stamina, 86 int, 56 spirit, 74 crit, 131 SP. |
| Shoulders | Spaulders of the Wayward Conqueror | PaladinPriestWarlock | 10. T8 Shoulder Token for Paladin, Priest, Warlock. |
| Shoulders | Spaulders of the Wayward Protector | WarriorHunterShaman | 10. T8 shoulder badge for warrior, hunter, shaman. |
| Shoulders | Spaulders of the Wayward Vanquisher | RogueMageDruidDeath Knight | 10. T8 Shoulder Token for Rogue, Mage, Druid, DK. |
| Neck | Shallow Grave Pendant | PriestMageWarlockShamanDruidPaladin | 10 HARDMODE, ilvl 239. Neck heal/caster: 51 stamina, 49 int, crit, haste, 84 SP, yellow socket. |
| Hands | Thunder God's Gauntlets | Paladin | 10 HARDMODE, ilvl 239. Plate, healing: 58 stamina, 64 int, crit, haste, 113 SP, 2 sockets. |
| Weapons | Combatant's Bootblade | RogueDruid | 10 HARDMODE, ilvl 245. One-handed dagger 1.40: 50 agility, 45 stamina, crit, haste, 84 AP, 1987 AP in beast form. |
| Accessory | Mjolnir Runestone | WarriorRogueHunterShamanDeath KnightDruidPaladin | 10 HARDMODE, ilvl 239. Physical DPS trinket: 115 crit + proc 751 ArP for 10 sec (15%, CD 45 sec). |
| Accessory | Sif's Memory | PriestMageWarlockShamanDruidPaladin | 10 HARDMODE, ilvl 239. Cast/heal trinket: 124 SP + proc of replenishing 220 mana every 5 sec for 15 sec. |
| Head | Crown of the Wayward Conqueror | PaladinPriestWarlock | 25. T8.5 helmet token for paladin, priest, warlock. |
| Head | Crown of the Wayward Protector | WarriorHunterShaman | 25. T8.5 helmet token for warrior, hunter, shaman. |
| Head | Crown of the Wayward Conqueror | RogueMageDruidDeath Knight | 25. Helmet token T8.5 for rogue, mage, druid, DC. |
| Belt | Belt of the Deceived | HunterShaman | 25. Chain mail, physical dps: 60 agility, 71 stamina, 45 int, crit, 180 AP, AP. |
| Legs | Leggings of Lost Loves | PriestMageWarlock | 25. Fabric, heal/caster: 105 stamina, 86 int, 91 spirit, haste, 122 SP, 2 sockets. |
| Ring | Sif's parting words | WarriorPaladinDeath Knight | 25. Ring str-dps: 76 strength, 76 stamina, crit, skill. |
| Accessory | Scale of Fates | PriestMageWarlockShamanDruidPaladin | 25. Cast/heal trinket: 132 SP + yuz 457 haste for 20 sec (CD 2 min). |
| Weapons | Valmir, northern storm | RogueShamanDruid | 25, ilvl 238. One-handed blunt weapon 2.60: 55 agility, 54 stamina, accuracy, 78 AP, mastery, 1846 AP in beast form. |
| Head | Defender Military Helmet | WarriorDeath Knight | 25 HARDMODE, ilvl 252. Plate, physical dps: 139 strength, 165 stamina, crit, accuracy, meta + yellow socket. |
| Shoulders | Combatant's Pauldrons | Shaman | 25 HARDMODE, ilvl 252. Chain mail, heal/caster: 93 stamina, 79 int, haste, 35 mp5, 105 SP, 2 sockets. |
| Chest | Gladiator's Garb | RogueDruid | 25 HARDMODE, ilvl 252. Skin, physical dps: 128 agility, 145 stamina, crit, haste, 160 AP, 3 sockets. |
| Ring | Fatal vice | WarriorPaladinDeath Knight | 25 HARDMODE, ilvl 252. Tank ring: 58 strength, 109 stamina, defense, evasion, skill. |
| Left hand | Stronghold of Wisdom | PaladinShaman | 25 HARDMODE, ilvl 252. Shield, heal/caster: 8563 armor, 79 stamina, 54 int, crit, haste, 85 SP, blue socket. |
| Ranged | Skyforged Crossbow | Hunter | 25 HARDMODE, ilvl 252. Crossbow 2.80: 45 agility, 45 stamina, crit, accuracy, 65 AP. |
| Accessory | Shard of Val'anyr | PaladinPriestShamanDruid | 25. Legendary Fragment: 30 shards = Val'anyr, Hammer of Ancient Kings. |