Kel ' Thuzad ( tactics ) Kel ' Thuzad , once a sorcerer of the Kirin Tor of Dalaran , is the chief lieutenant of the powerful Lich King . He rules over the Dragonblight from his citadel of Naxxramas . He was originally voiced by Michael McConnohie but the current voice actor is unknown . He is the final boss of the re - tuned raid dungeon Naxxramas in Wrath of the Lich King . Background . Formerly a sorcerer of Dalaran , Kel ' Thuzad was one of the principal agents of the Lich King , responsible for the spreading of the Plague of undeath across Lordaeron . After being slain by Arthas during the events of the Third War , he was reborn as a lich . He then aided Arthas in summoning Archimonde , a powerful lord of the Burning Legion . However , Kel ' Thuzad ' s true loyalty was to the Lich King , and not the Burning Legion . After the Legion ' s defeat , Kel ' Thuzad supported Arthas in wresting power from the Dreadlords . When Arthas left for Northrend during the events of The Frozen Throne , he left Kel ' Thuzad as his agent to command the Scourge in Lordaeron . He now commands Scourge forces in the Dragonblight from his necropolis floating above Wintergarde Keep , Naxxramas . For much more information , see : 25 - man abilities . Phase one . Kel ' Thuzad begins the encounter invulnerable , and you need to kill adds which come from the seven alcoves of the room . This includes the entrance . Phase two . Kel ' Thuzad becomes active 3 minutes and 48 seconds after you engage him . Kel ' Thuzad has approximately 14 , 660 , 000 hit points . He is tauntable . Frost Bolt single Two - second cast . Inflicts 29 , 250 to 30 , 750 Frost damage and reduces movement speed of primary aggro target for 4 seconds ; must be interrupted . Frost Bolt is cast at random intervals and is often chain - cast ; having multiple Rogues and Warriors meleeing Kel ' Thuzad at all times is ideal . This spell cannot be reflected via Warrior Spell Reflection . Frost Bolt multiple An instant cast that inflicts 7200 to 8800 Frost damage and reduces the targets ' movement speed for 4 sec . Hits everyone in the room and cannot be interrupted . Used every 20 - 30 secs . Fully resistible . Chains of Kel ' Thuzad Kel ' Thuzad can mind control 3 people at once . Size increased by 200 % . Charmed . Damage increased by 200 % . Healing increased by 500 % . They will buff and heal Kel ' Thuzad , a Deathknight with skilled and glyphed Rune Tap can heal Kel ' Thuzad for over 700 , 000 damage , so be careful . Can be CC ' d by any ability that would normally work on humanoids . With the Ulduar patch this ability will no longer reset raid threat . Unlike Kel ' Thuzad 40 , this will not mind control the main tank . This ability lasts 20 seconds and cannot be removed by any means . This spell has a 90 - second cooldown . Chains of Kel ' Thuzad are a specially crafted set of seven magical , spiked chains , given to him by Ner ' zhul . The owner must wrap this artifact around his body to activate it , at which point the chains animate and move lazily to and fro in the air when not being commanded . Mana Detonation A debuff randomly applied to a mana - using player . The player will explode after 5 seconds , dealing Arcane damage based on maximum mana to all players within 10 yards ( not to himself ) . Mana - based melee will only deal ~ 10 , 000 damage , while holy Paladins and Priests can cause ~ 25 , 000 damage or more . It will also drain ~ 2 , 000 mana from the affected player . This spell has a 30 - second cooldown . Shadow Fissure Summons a very noticeable red fissure around the targeted player which does 62500 - 137500 Shadow damage after 5 seconds as Void Blast . Easily avoidable by running out of the fissure . Frost Blast Places an Ice Block effect on the targeted player and all players within 10 yards , rendering them unable to perform any action . This effect will continue to chain to anyone within 10 yards of anyone affected , as with C ' thun ' s Eye Beam . It will deal 104 % of their maximum HP in damage over 4 seconds . If those affected are not healed within 4 seconds , they will die . Unlike 10 - man , this ability can target the main tank . This spell has a 45 - second cooldown . Phase three . At 45 % health , phase three will begin as Kel ' Thuzad calls for aid and the Lich King sends four Nerubian Crypt Lords known as the Guardians of Icecrown to attack the raid . 10 - man abilities . Phase one . Kel ' Thuzad is invulnerable , and you need to kill adds which come from the seven alcoves , including the entrance . Phase two . Phase two begins 3 minutes and 48 seconds after you engage Kel ' Thuzad . He becomes active , and has approximately 5 , 660 , 000 hit points . He is tauntable . Phase three . At 45 % health , Phase Three will begin as Kel ' Thuzad calls for aid and the Lich King sends two Nerubian Crypt Lords known as the Guardians of Icecrown to attack the raid . 25 - man strategy . You will need one main tank and two to three Guardian - of - Icecrown offtanks for this encounter . It is worth noting that none of the abilities in this encounter can be removed by PvP trinkets or Ice Block / Divine Shield / Cloak of Shadows . During phase one , the raid will stack in the centre of Kel ' Thuzad ' s room . Melee will engage and kill Unstoppable Abominations while ranged will kill Soldiers of the Frozen Wastes and Soul Weavers before they reach the raid . 15 seconds after Kel ' Thuzad ' s aggro emote , he will become active ; it is essential that the entire raid spread out efficiently around the room before this occurs in order to mitigate the effects of the Mana Detonation and Frost Blast abilities . Mana Detonation will come approximately every 20 to 25 seconds , Shadow Fissure approximately every 15 to 20 seconds , Chains of Kel ' Thuzad every 90 to 120 seconds , and Frost Blast every 45 to 60 seconds . For phase two , the main tank should drag Kel ' Thuzad to the center of the room , and melee classes should stack in the three cardinal points around Kel ' Thuzad ' s hitbox not occupied by the main tank ( a bit more than 10 yards from each other ) . It is critical that they be at max range and spread out so that Frost Blast will only hit as few as possible . This is a diamond - shaped formation . If this positioning is not perfected , multiple melee will be frozen by Frost Blast which tends to result in the death of most of them . If it chains to the tank , it usually results in a wipe . An interrupt rotation on Kel ' Thuzad ' s Frost Bolt should be established to reduce damage taken by the tank ( 30k damage per bolt without resistance ) . If / when Shadow Fissure is cast on the tank , the melee MUST reposition with the tank . The ranged DPS and healers should spread out in a circle around Kel ' Thuzad with a space left for mana - based melee to run to should they be afflicted by Mana Detonation . Melee will need to move for Shadow Fissure but should move back to their original position afterward . The Guardian - of - Icecrown offtanks don ' t need to do anything until phase 3 begins and can stay in the alcoves where the adds spawned in phase one to avoid spreading Frost Blast . Usually at least once before phase 3 begins , Kel ' Thuzad will cast Chains of Kel ' Thuzad . All DPS must stop until the tank has reestablished threat on Kel ' Thuzad . Interrupts need to continue . It is important that Mages polymorph and other classes CC the affected players very quickly as they will do extremely high damage ( two - shotting raid members ) and cast extremely large heals on Kel ' Thuzad . It is also possible for Kel ' Thuzad to be Bloodlusted and Hand of Protectioned , as well as any other buffs you can think of . When Chains of Kel ' Thuzad ends , the affected players should return to their positions . At 45 % HP , the Lich King will send four Guardians of Icecrown to attack the raid . These appear one at a time . The Guardian offtanks will need to pick up the rest and offtank them in the alcoves for the rest of the encounter . All of Kel ' Thuzad ' s phase - 2 abilities continue in this phase . Note that it is possible and probable that one of your Guardian offtanks will be mind controlled at some point , so it is advisable that the Guardians are tanked relatively close together so that the other offtanks can taunt the Guardians when they become loose . Guardians hit very hard and their melee hits will increase the longer you take to kill Kel ' thuzad . It is advisable to save DPS cooldowns and Bloodlust for phase 3 as the Guardians will become untankable if you take too long to finish the encounter . 10 - man strategy . The 10 - man version of Kel ' Thuzad is " significantly " easier than the 25 - man and should be manageable if your group can kill Sapphiron . Since the Guardians do not hit very hard on 10 - man and Kel ' Thuzad cannot target the main tank with Frost Blast , the main tank can pick up both Guardians and tank them along with Kel ' Thuzad , eliminating the possibility of the offtank being Frost Blasted while tanking Guardians , which can often result in death . ( Pre - Patch ) Kel ' Thuzad ' s abilities in a 10 - man consist of single - target Frost Bolts ( which can be interrupted ) , raid - wide Frost Bolts ( which must be healed through ; the slowing effect can be dispelled ) , Mana Detonation ( positional ) , and Shadow Fissure ( instant death if in the area of effect after 5 seconds ) . Healers must keep the raid topped off , and heal the Frost - Bolted target immediately . Optimally , designate one healer for the tank , healer ( s ) to watch for Frost Blast , and AoE / chain heals for the raid - wide Frost Bolts . The healer assigned to heal the multiple Frost Bolt should stand near the center of the raid to have access to the entire raid . Healers should also be ready to heal each other in case of Frost Blasts , and to fill in for each other as needed . Once the adds are picked up , this encounter is effectively a DPS race , because the guardians get bigger and bigger , and hit harder , until eventually your tank will die or your healers run out of mana . While not as big a problem as on 25 - man , restrict your melee DPS to three , including the tank . This allows them to form a triangle around Kel ' Thuzad , which prevents frost bolts chaining onto the tank . The tank may have difficulty seeing the fissures once the Guardians grow to a certain size . To deal with this , try to move every time they form . This will not be an issue if your group has enough DPS to kill Kel ' Thuzad before the Guardians get too big . Kel ' Thuzad ' s can chain cast his single - target Frost Bolt on a tank for 10 - 12k each . Any form of melee interruption is greatly helpful here , including a Shield Bash , Rogue Kick , or Death Knight Mind Freeze / Strangulate . Kel ' Thuzad has a 19 - minute enrage timer ( from the beginning of the fight ) , at which point his Frost Bolts begin hitting for approximately 30k and he hits for 20k melee on plate . Quotes . " See Kel ' Thuzad for quotes from his WCIII script . " Dialogue with the Lich King upon death of Sapphiron ( this dialogue has changed since the original inception ) : Death of Mr . Bigglesworth : Taunts when the final bosses of the first four wings are killed : Phase One : Phase Two : Phase Three : Mana Detonation : Dispelling Chains of Kel ' Thuzad : Frost Blast : Killing a player : Death : Videos . Solo encounter . How to solo Kel ' Thuzad as a lvl 85 Protection Paladin 25 - man encounter . < nowiki > < youtube > u - 00LznnK70 < / youtube > < / nowiki >