Kil ' jaeden ' s war against the Lich King The Kil ' jaeden ' s war against the Lich King was a conflict fought primarily between the factions of the Burning Legion and the Undead Scourge . Its events were chronicled in " " . Prelude . At the end of the Third War , the Great Alliance was able to defeat Archimonde at the Battle of Mount Hyjal . While Archimonde was dead , the aftermath and legacy of the invasion was far from over . While the Horde under Warchief Thrall and the humans under Jaina Proudmoore established their respective counties , the Night Elves decided to return back to their homelands , to not only repair the damage to Kalimdor , but to also accept that they were now mortal beings . Kil ' jaeden , knowing Ner ' zhul ' s betrayal and aid to the Night Elves , decided to eliminate him first . Finding the recently exiled Illidan Stormrage , and promising him power beyond imagination , Kil ' jaeden gave Illidan the Orb of Kil ' jaeden , and the task of destroying the Lich King . Looking into Gul ' dan ' s memories , and finding out about the Tomb of Sargeras , Illidan decided to use the Titan ' s power to destroy the Lich King . He would later receive assistance from the Highborne - turned Naga in escaping Kalimdor to proceed with his plan . Eye of Sargeras . The warden , Maiev Shadowsong , once Illidan ' s jailor , was eager to recapture her prisoner , believing that he had become more unstable thanks to The Skull of Gul ' dan . Accompanied by Naisha , she initially pursued Illidan to the end of Kalimdor , where she followed him to the Broken Isles . Establishing a base and learning of the island ' s history from Drak ' Thul , Maiev discovers that Illidan is planning to use the powers of the fallen Titan , Sargeras , to receive even more power . Fighting her way through the demons and guardians of the tomb , Maiev arrives to see Illidan claim the Eye of Sargeras for himself , and he uses the newfound power to bury the tomb , along with Maiev and the watchers that joined her . While Maiev was able to escape , Naisha and the rest of the watchers perished under the tomb . Now on the disadvantage , the warden manages to send a runner to inform both Malfurion Stormrage and Tyrande Whisperwind of Illidan ' s recent actions . Believing that letting him go was now a mistake , the pair arrive on the Broken Isles , and manage to assist Maiev in forcing back Illidan and the Naga . The trio chase Illidan all the way to Lordaeron , where Malfurion temporarily parts ways with the two to commune with the land of Lordaeron . While separated , Maiev and Tyrande encounter Prince Kael ' thas Sunstrider of the elves of Quel ' thalas . He informs them of the formation of the Blood Elves and the destruction of his home country . Bringing supplies for the Alliance , the Night Elves decide to aid Kael ' thas , in exchange for his help in hunting Illidan . During the movement of the caravan , a large undead army swarms the elves , causing Tyrande to have a stand - off against them at a bridge to give time for Kael ' thas and Maiev to leave . Though she is able to stop the advance , the bridge she fights on collapses , and the priestess is swept by the river . Kael initially attempts to rescue Tyrande , but relents on Maiev ' s insistence that he aid her hunt . Having finished speaking with the trees and finding out of Illidan ' s plot of using the Eye of Sargeras to melt the ice caps of Northrend , Malfurion returns to inform Maiev and Tyrande of the plan , but finds the latter missing . Maiev then proceeds to lie that Tyrande was killed fighting the undead , and the two , soon accompanied by Kael , face off against Illidan . Stopping his ritual , Illidan reasons his attempt to stop the common enemy of the Lich King , but Malfurion retaliates that Illidan ' s recklessness had caused Tyrande ' s death . Interjecting into the conversation , Kael tells Malfurion that Tyrande was simply swept by the river current , and that it was premature to declare her dead . Realizing the deception , Malfurion immediately restrains Maiev , and allows Illidan to aid him in their attempt to rescue the priestess . Kael , on the other hand , parts ways with the Night Elves in order to join the remaining Alliance forces in Lordaeron under Lord Garithos . Illidan ' s exile . With the brothers working together for the first time in ages , Malfurion and Illidan find Tyrande barely holding out against a massive Undead Army . Allowing himself to hold the undead army back , Malfurion leaves Illidan with the task of reaching and saving Tyrande because of how the Naga are able to reach her faster through the river . Not betraying his brother ' s trust , Illidan returns with Tyrande , and the two brothers make amends . Knowing that Kil ' jaeden would likely be angered at his failure to destroy the Lich King as well as getting sidetracked , Illidan decides to leave Lordaeron through a portal . Maiev , having broken free , led her remaining Watchers into the portal in pursuit . Despite Tyrande ' s attempts to dissuade Maiev and to explain that Illidan had atoned for his crimes , the priestess is stopped by Malfurion , who states that Maiev has now become the embodiment of vengeance and is utterly consumed for the hunt . The pair soon return back to Kalimdor . Blood Elves . Joining up with the Alliance forces , Kael met Lord Garithos , who tasked Kael with the repair of the observatories over the remains of Dalaran . Unhappy with both the task and the commander ' s racist remarks , Kael begrudgingly accepts the task nonetheless . During the mission , he encounters Lady Vashj , previously affiliated with Illidan . She provides boats for him upon the discovery that the nearby Goblin Shipyard had been destroyed by the undead . Accomplishing the task , Kael is once again insulted by Garithos for having accepted the aid of the Naga to complete it . Later Kael is ordered to fight and destroy nearby encampments of the undead , but most of his forces were recalled to Garithos ' own . Left with no choice , Kael once again accepted the aid of the Naga , and was able to not only prevent the destruction of his brethren , but also accomplish the task . The two later converse , and Kael admits that the remaining elves have become power - hungry thanks to the loss of the Sunwell . Soon a Spell breaker informs the two that Garithos had arrived , and Vashj and her Naga quickly leave , but not before being spotted . Having grown incensed with the elves for accepting the aid of the Naga , Garithos proceeds lock up Kael and the remaining blood elves in the Violet Hold with the intent of executing all of them . Unexpectedly , Vashj sneaks in through the sewers , and assists Kael in freeing the remaining blood elves . Once all of his men were assembled , Vashj opened a portal to Outland , and Kael ordered his men to cross immediately . During the process , Garithos attempted to destroy the portal by using explosives , though the elven forces were able to reconstruct old towers of Dalaran to aid in their escape . Having escaped to Outland , Vashj tells Kael that the person that can aid him is none other than Illidan . As the two traverse Outland , they soon spot that Maiev has managed to capture Illidan and has locked him in a cart . Attacking her en - route , and securing Illidan , the pair release Illidan , and he states his plan on escaping from Kil ' jaeden ' s wrath . Planning to first cleanse Outland of Kil ' jaeden ' s agents , he moves to take Outland from the Pit Lord Magtheridon . Race to Icecrown . Having reached Northrend , Arthas is greeted by Kael ' Thas after destroying a scouting encampment , and he declares that both he and Illidan will stop Arthas at all costs . Receiving information of a shortcut from Anub ' arak , Arthas kills the blue dragon , Sapphiron , and resurrects it as a massive Frost Wyvern that helps them plow through the Blood Elf and Naga defense . Surprised to not see the forces he left behind , Anub ' arak and Arthas soon find that the dwarves of Muradin Bronzebeard had regrouped under Baelgun Flamebeard and had since taken refuge in the Shadow Web Caverns . Defeating the dwarves , the undead soon run into the Forgotten Ones , and kill a Faceless One to escape the Caverns and reach the Icecrown . Although Illidan , Kael and Vashj had already established their own bases , Arthas and Anub ' arak were able to secure enough time for Arthas to reactivate the four obelisks of Icecrown . In a final bid , Illidan duels Arthas , but is wounded and defeated , eliminating the final obstacle between Arthas and the Lich King . Aftermath . Illidan ' s failure to defeat the Lich King allowed Arthas to unquestionably become one of the most powerful beings on the world . Though he initially had issues in order to become the dominant personality , he was able to banish his human side and suppress Ner ' zhul ' s spirit . As the Lich King , Arthas would kill many and perform multiple inhumane acts to lure unsuspecting heroes that would dare to challenge him , so that he would kill them and raise them as his greatest champions . Illidan never fully recovered from this defeat , and he became paranoid upon returning to Outland . Illidan ' s subsequent breakdown eventually caused Kael ' thas to abandon Illidan in favor of serving Kil ' jaeden instead . Seeing Illidan ' s insanity , Akama used this opportunity to free Maiev , and the two , along with a group of heroes , defeated Illidan and ended his control over the Black Citadel .