BossAscendant Lord Obsidius
Image of Ascendant Lord Obsidius
Gender Male
Race Earth ascendant (Elemental)
Level 32-37 Elite
Reaction Alliance Horde
Location Scar of the Worldbreaker, Blackrock Caverns
Status Killable
Blackrock Caverns

Rom'ogg Bonecrusher
Corla, Herald of Twilight
Karsh Steelbender
Ascendant Lord Obsidius


Ascendant Lord Obsidius is the last boss of Blackrock Caverns in World of Warcraft: Cataclysm.


Adventure Guide

For his unyielding devotion and penchant for cruelty, the powerful shaman Dessirik the Depraved was gifted with ascension: a dark ritual that infused him with elemental powers, transforming him into a monstrosity known as Ascendant Lord Obsidius.


  • Spell shadow mindtwisting.png  Transformation Important — When Ascendant Lord Obsidius reaches 69% and 34% of his remaining health, he will randomly target one of the Shadows of Obsidius and jump into it. This results in Obsidius and the Shadow switching places.
  • Ability golemthunderclap.png  Stone Blow — Ascendant Lord Obsidius strikes with a strong attack, inflicting 150% of his normal melee damage and stunning his current enemy target for 1 sec.
  • Spell shadow demonicempathy.png  Twilight Corruption Magic Effect — Ascendant Lord Obsidius corrupts a random enemy player, inflicting 4000 Shadow damage every 2 seconds for 12 sec.
  • Spell nature thunderclap.png  Thunderclap Heroic Difficulty Magic Effect — Ascendant Lord Obsidius slams the ground, inflicting 11250 to 12750 Nature damage and reducing the movement speed of nearby enemies within 25 yards by 50% for 8 sec.
  • Shadow of Obsidius — Ascendant Lord Obsidius fights alongside two Shadows of Obsidius. These ephemeral constructs absorb all incoming damage. In Heroic Difficulty, Ascendant Lord Obsidius will fight with three Shadows of Obsidius.
    • Spell shadow misery.png  Twitchy — Shadows of Obsidius will attack the enemy who has most recently generated threat, instead of the enemy with the greatest amount of threat.
    • Spell shadow gathershadows.png  Crepuscular Veil Healer Alert — Shadows of Obsidius that swing at their current enemy cause all healing dealt to their target to be reduced by 24% for 4 sec. This effect stacks up to 4 times.


When you first arrive in the area Ascendant Lord Obsidius will be surrounded by many assistants—all but two (heroic: three) of whom will be eliminated when Raz makes his final appearance. The remaining assistants will aggro the player who most recently attacked them, and when they get close to their target, will channel a debuff (while on the run!) that reduces the effectiveness of healing.

Assign a DPS party member, preferably one with multiple instant ranged attacks (or AoE snares) to kite the assistants around, keeping them off the tank, for the duration of the fight. The assistants do not deal much damage, so this role is reasonably safe for a even a cloth-wearer. On heroic, Obsidius will periodically use Thunderclap; the kiter should therefore stay well away from the boss to avoid getting snared himself.

Twice during the fight, everything will stop for a moment while Ascendant Lord Obsidius changes bodies into one of his assistants. The new Ascendant Lord Obsidius will grow back to his former enlarged state, and everyone will need to switch targets and resume kiting/DPS. Tank threat is transferred; however, the kiter will need to pick up the assistant left in place of Obsidius.

Obsidius will cast Twilight Corruption, dealing 24000/48000 damage over 12 seconds on a random player; this magic DoT debuff should be dispelled.



Objective of

Related achievements


You come seeking answers? Then have them! Look upon your answer to living!
Killing a player
Your kind has no place in the master's world!
Switching shadows
Earth can be shaped, molded... You cannot! You are useless!
I cannot be destroyed... Only de... layed...



Patch changes

External links