Kael'thas Sunstrider


 * "I stand only for the elves now - for the sin'dorei. The children of the blood."
 * — Prince Kael'thas Sunstrider

Kael'thas Sunstrider was a senior member of the Kirin Tor and the Prince of Quel'Thalas, the last of the Sunstrider Dynasty. After the Fall of Quel'Thalas, Kael'thas led what remained of his people in the service of the Alliance. Striving to placate his people's addiction to magic, he later covertly allied with Illidan Stormrage and the Burning Legion. He was branded a traitor after his allegiance with the Legion was revealed. Kael'thas plotted to summon Kil'jaeden the Deceiver through the Sunwell, but his plans were foiled by the Shattered Sun Offensive and the sacrifice of Anveena Teague. He was defeated by their forces in Magisters' Terrace.

Dalaran
Prince Kael'thas was a powerful mage and member of the Six, the shadowy high council of the Kirin Tor. Prior to the Second War, he and the other members of the high council questioned Khadgar about the orcs and the events in Karazhan that led to the death of Medivh. Around this time, his father King Anasterian displayed concern for his son's loyalty - which Anasterian worried was torn between the Kirin Tor fully and Quel'Thalas.

Despite his status as both Quel'Thalas' royal prince and his (rumoured) place on the Council of Six, Kael'thas proved himself an approachable individual, and quickly took to Lady Jaina Proudmoore. His charm and "perfectly" handsome features impressed the young sorceress, though his regality and her longing for Prince Arthas Menethil of Lordaeron had her rebuke his advances - such as traveling to visit the beautiful elven homeland, Quel'Thalas, where magic was even more commonplace than Dalaran. Arthas, in turn, came to view the older and more powerful Kael with jealousy, knowing that if push came to shove, Kael would end up victorious. Later, Arthas himself was to visit Dalaran to study, and Jaina began a relationship with him. Kael'thas did not take kindly to this, and upon discovering it simply feigned mild surprise that Arthas would be so secretive about having a woman such as Jaina.

Kael'thas was opposed to the notion of upkeeping the internment camps, viewing the orcs' inability to control their dependancy on demon blood as a testament to their lack of formidability as a people. This brought him into conflict with Antonidas, Jaina and Arthas, who had come to believe that sentient individuals - lethargic or not - should be shown mercy, and that the orcs were not beyond salvation.

Such minor ponderings, however, would soon become the least of Prince Kael'thas' concerns.

Third War
After a dramatic turn of events, the treacherous Prince Arthas ravaged his own homeland, and led an attack on Quel'Thalas. His brutal conquest of the elven kingdom resulted in the utter destruction of Silvermoon City, the defiling of much of the high elven forests, the annihilation of the legendary Sunwell (thus forcing a withdrawal-based lethargy on the elves), the total slaughter of around 90% of the high elven race, and the killing of Kael's father, High King Anasterian Sunstrider.

Kael'thas learned of this while in Dalaran, and a remorseful Jaina attempted to console him. Kael'thas lashed out at her, berating her for her relationship with such a butcher, and made one final allusion to the fact that she had chosen such a monster over him. Cursing humanity, viewing himself as a fool for ever assuming that humans could aid him, Kael'thas stated that his people had thus been reborn, by the blood of those who are forced to serve her "beloved" in death. With his father gone, Kael'thas knew that leading his people was now his duty alone.

Kael'thas abandoned Dalaran its fate, and rushed to the aid of his people. Organizing the survivors, Kael'thas evacuated as many of his people as he could, and came to burn several of the defiled forests in an act of scorched earth, to spite the Scourge invaders. Kael'thas then observed the defiled Sunwell himself, and witnessed the dark, twisted energies pulsating from it. Fearing a further catastrophe, Kael'thas destroyed the corrupted Sunwell. Though he had saved his people from continued exposure to the dark energy, the destruction of the Sunwell resulted in a withdrawal-based lethargy for the elven race.

Kael'thas renamed his shattered people "blood elves" in honor of their fallen brethren, and resolved to see Quel'Thalas shine once again.

Though King Anasterian had removed Quel'Thalas from the Alliance prior to the undead onslaught, Kael rejoined what was known as the "New Alliance" battling the Scourge in Lordaeron. Though this alliance was Kael's best bet for vengeance upon the Scourge, he came under the bigoted scrutiny of its prejudiced leader, Grand Marshal Garithos.

Kael'thas took a number of his most powerful followers to join the New Alliance, though the majority of his people remained behind in Quel'Thalas. Kael'thas commanded the great ranger, Lor'themar Theron, to safeguard the shattered elven kingdom, to protect their exhausted people, and to keep what remains of Quel'Thalas untainted from the Scourge. Before leaving, Kael'thas also managed to salvage the skull of his father, Anasterian, from the ruins of Quel'Thalas, as well as the broken runeblade Felo'melorn, which he later reforged.

The Hunt for Illidan
Following the destruction of Silvermoon, Kael began to notice an emptiness within himself and his brethren, an insatiable hunger and disharmony. However, there was no time to deal with that, as Kael had other duties.

Kael and his soldiers were stationed in the Silverpine Forest when a disturbance began to rile up the undead in and around Dalaran. They had begun to raid the outposts Kael had established, so he gathered up his forces to seek refuge in the relative safety on the other side of the River Arevass.

As he was loading the supply wagons, he was met by two unexpected strangers, Maiev Shadowsong and Tyrande Whisperwind. These night elves had pursued Illidan Stormrage for three days across the sea. Kael guessed that perhaps Illidan was behind the disturbances at Dalaran, and when he told them his tale, Tyrande immediately offered her assistance, thinking that he could help them track down Illidan. Maiev believed it to be a waste of time, but reluctantly agreed. With the protection of the night elves and their Mountain Giant allies, Kael quickly made his way to Pyrewood Village to retrieve his buried supply caches. As they gathered more reinforcements, Maiev asked Kael where the rest of his brethren were, and he told them of the destruction of Quel'Thalas. Tyrande empathized, but warned that vengeance and rage was not a pleasant road to walk.

As they arrived in Pyrewood, the undead were lying in wait and ambushed the caravan. Kael, Maiev, Tyrande and their forces battled off the first attackers, but as the second wave advanced, they realized that the caravan would never survive another assault. Maiev and Kael rushed the caravan across the bridge, while Tyrande stayed to fend off the undead alone. As she called upon the powers of Elune to protect her, the bridge fell away, and Tyrande was swept down the river. Kael wanted to pursue her, but Maiev stopped him, saying that she was a warrior and knew the risks. Maiev then demanded that Kael honour their bargain, and help her capture Illidan.

Kael and Maiev tracked Illidan to Dalaran, where Kael's scouts found him performing a strange ritual with a mysterious gem. Malfurion came and told them that Illidan's spell was using the Eye of Sargeras to break Northrend apart. Immediately, they advanced upon his location, while Kael defended their bases from the voracious undead. When Illidan's spell was interrupted, Malfurion approached his brother and condemned him for his part in Tyrande's death. Kael, perplexed, suggested that it was premature to assume she was dead, and was vehemently silenced by Maiev.

Malfurion, realizing he had been duped, left Maiev entangled in vines while he and Illidan set off to save Tyrande. Maiev eventually freed herself and set off in pursuit, while Kael'thas was left in the ruins of Dalaran.

The Rise of the Blood Elves
Kael found the Grand Marshal Garithos at Dalaran, who dismissed his story of the night elves as a fanciful excuse. Garithos, Kael's commanding officer, harbored a poorly-hidden disdain for all non-human races. Garithos informed Kael that a strikeforce was encroaching on Dalaran, and that he was going to head them off at the mountains. Kael was quick to volunteer his assistance, but Garithos had other plans. He explained that a second force was believed to be approaching from the east, and that the arcane observatories needed repairs so that they could be used to spot them. Kael did as ordered, but when he came to Lordamere Lake, he found the shipyard ruined, and had no route across the water. Lady Vashj, a naga witch, soon arrived to offer her aid, citing their common ancestry. Vashj gave him boats, which Kael used to ferry his troops to the outlying observatories.

When Garithos returned from the front, he condemned Kael for consorting with the naga, despite the prince's assurances that they were not a threat to the Alliance. Garithos warned Kael that he would not tolerate treason before leaving Kael to keep things in line at Dalaran. An emissary sent by Garithos arrived the next day with further orders, reporting that the observatories had detected an undead force in the west. Kael was to defeat them, though the emissary also recalled his foot soldiers, cavalry, and support teams to the front lines. Kael was left with only his fellow elves to aid him, and the undead were quick to overtake the outposts across the river. Once again, Lady Vashj arrived with her naga, and though Kael was wary of accepting her offer, she insisted that without her help, he and his brethren would surely fall. Realizing that it would be impossible to survive without these reinforcements, Kael accepted. Together they defeated the undead.

After the battle, Kael told Vashj about how his people felt an emptiness ever since Quel'Thalas was destroyed. Vashj explained to Kael that just like the naga, his people were addicted to magic. Without the Sunwell to give them a constant supply of magical energies, they would surely suffer a fatal withdrawal. Kael heard Garithos approaching, and bid Vashj to flee, but Garithos' men saw the naga escaping and arrested Kael and his people for treason. Garithos smugly told Kael that he now had all the proof he needed to deal with him and the other elves as he felt they deserved, and he had them all imprisoned in the Dungeons of Dalaran.

Vashj crept in through the sewers of the dungeons and freed Kael, then helped him free his brethren. Vashj promised him escape from his human oppressors through Kel'Thuzad's interdimensional portal, where her master, Illidan, was waiting on the other side. As they neared the exit, Kael met his former comrade, Jailor Kassan, who he was forced to slay in order to escape. Upon leaving the dungeons, the blood elves and naga fled through the portal Archimonde used to enter the world of Azeroth, and into a new world.

Kael found himself on the barren lands of the Hellfire Peninsula, and Vashj revealed that this Outland was once the orcish homeland of Draenor. They searched for Illidan for days, until Vashj caught a familiar scent on the winds. Maiev had captured Illidan and was escorting him back to her base in a prison wagon. Kael and Vashj's forces quickly rushed into the fray and battled Maiev's army in order to retrieve the unconscious Illidan and return him to their base, where they could undo the magical lock that kept him caged.



Illidan was pleased with the tenacity of all his servants, new and old alike, and told them of the situation in Outland. To flee from his vexed master, Kil'jaeden, Illidan had fled to Outland only to find it overrun by Magtheridon and his fel orcs, reinforced by demons arriving through Ner'zhul's dimensional gates. Kael had hoped Illidan might be able to cure the blood elves of their addiction to magic, and asked if he could help them. Illidan sadly told him that there was no cure for their condition, but promised Kael that if he joined him, he would provide the blood elves with enough magical energies to keep their hunger sated forever. Upon hearing this, Kael pledged his loyalty to Illidan. The blood elf Rommath was sent to spread Illidan's message of a new homeland to Quel'Thalas.

Kael and Vashj protected Illidan as he went about closing the interdimensional gateways. Kael discovered a camp of draenei being assaulted by orcs, and lent them his aid. He was greeted by Akama, the Elder Sage, who offered his allegiance to Illidan. Finally, the time came to assault Magtheridon's Black Temple. Illidan, Kael, Vashj, and Akama all led their forces against Magtheridon's fortress, infiltrating it and finally defeating Magtheridon in his own throne room.

As Illidan stood triumphant, Kil'jaeden descended from the fiery sky and rebuked Illidan for his insolence in trying to hide. The demon gave him one last chance to save himself - destroy the Frozen Throne, or face his eternal wrath.



Assault on the Frozen Throne
Kael and his new allies returned to Northrend, where they were immediately met by Anub'arak and his troublesome race. Though they kept them at bay, Illidan's forces slowly advanced on the Icecrown Glacier.

The blood elves, thirsty for vengeance, attacked the newly arrived Arthas in a large-scale Dragonhawk ambush. Arthas was able to push them back, with the help of his nerubian ally, Anub'arak, and was greeted by a familiar sight - Kael'thas, brandishing a reforged Felo'melorn. After a heated exchange, Arthas charged the elven prince, though Kael'thas teleported out of the fray for the time being. Arthas fled into Azjol-Nerub, and after his ascent out of it, Kael'thas attacked him once more.

The two appeared to be fairly evenly matched; Felo'melorn proving an adequate counter to the mighty Frostmourne. However, the tides began to turn, and despite Kael's vicious assault of both powerful fire spells and Felo'melorn's precision, Kael'thas was pushed back by Arthas - the death knight empowered further by the Lich King's proximity. Knowing that he could not win this battle, and forced into the snow, Kael'thas once again teleported himself away; deeming that he had bought Illidan enough time.

As such, Arthas was left with only one more obstacle - Illidan himself.

After fierce combat, Arthas managed to get the best of Illidan, and Illidan's twitching body was tossed to the ground. Kael and Vashj were left leaderless on the snowy slopes of Icecrown as Arthas claimed his destiny. Together they took Illidan's unconscious body with them as they fled back to Outland.

World of Warcraft: The Burning Crusade
Kael'thas, together with 15% of the blood elven people, made the journey into Outland with his new allies. With the goal of finding a lasting method to sate the elven addiciton, and claiming a new homeland for the sin'dorei, Kael'thas thus put his plans into motion. However, he had not forgotten about his people still in Azeroth. Grand Magister Rommath, a powerful Archmage who had served Kael'thas' ambitions faithfully, was sent back to reclaim Quel'Thalas with a contingent of magisters - and to spread Illidan's teachings of draining magical power, teachings smoothly attributed by Rommath to the blood elven scion. Kael'thas named Lor'themar Theron Quel'Thalas' regent lord, to safeguard the country until the prince's return to lead their people. Emboldened by the reclamation of shining Quel'Thalas, and the prince's promises of a glorious future, the blood elves began to work towards their own great journey - to reunite with their prince in the promised haven of Outland.

To this end, the blood elves on Azeroth forged an alliance with the Horde.

Kael'thas, with some of his most powerful servants, claimed the magic-rich area of Netherstorm as his base of operations in Outland. Displaying his long-severed ties to the Kirin Tor, Kael'thas ordered the callous destruction of the local Kirin'Var Village and its residents. Kael'thas himself claimed the citadel of Tempest Keep as his own, and was able to overcome its powerful defenders - including a naaru, named M'uru, whom Kael'thas sent back to Silvermoon for his people to feed upon.

His attack on Tempest Keep also led to the outmanned draenei being forced to flee in their own vessel, the Exodar, though several of Kael'thas' agents were able to give pursuit. Upon the draenei vessel's crash into Azeroth itself, Kael remained in touch with his underlings and instructed them to create a portal - the Sun Gate - capable of allowing reinforcements from Tempest Keep to arrive and slaughter the draenei.

Kael'thas later sent Voren'thal the Seer and his forces to attack Shattrath City and the Sha'tar, though Voren'thal threw down his weapons and defected. This betrayal was a devestating blow to Kael'thas, as Voren'thal's ranks included some of the most gifted magisters and scholars he had led into Outland.

The skull of his father, King Anasterian, is still in his possession and is among the artifacts that the red and green dragonflights thought would be needed to restore the Sunwell. He also has in his possession one of the Vials of Eternity, granted to him by Illidan, as did Vashj.

An Unholy Alliance
The Scryers soon discovered that Kael'thas had with the Burning Legion.

Kael'thas, aware of Illidan's insanity (brought on by his defeat at the hands of Arthas Menethil at Icecrown, nearly four years earlier), "switched paymasters accordingly" according to Magister Theledorn. Kael's decision to ally himself with the Burning Legion not only led him to betray Illidan, but also the Horde and his own people - the many blood elf pilgrims and adventurers traveling from Azeroth. At Manaforge Ara, agents of the Burning Legion bearing orders from Kael mingle with his Sunfury servitors.

The Scryers, recognizing that Kael's mad bid for power would lead the blood elven race to doom, continued to fight against Kael'thas and his forces in the hope of saving their people.

The Cipher of Damnation
Through spying on the Earthen Ring and their activities in Shadowmoon Valley, Kael'thas gained the knowledge of the Cipher of Damnation. The Cipher of Damnation was used by Gul'dan to sunder the orcs' connection to the spirits of the land, and may have been the same as (or similar to) the spell uttered by Thaurissan when he summoned the fiery destroyer Ragnaros to Azeroth.

Khadgar and A'dal discovered the plans of Kael'thas, and requested help from any able-bodied adventurers to prevent Kael'thas from ever using the Cipher of Damnation. Through their efforts the cipher was recovered, depriving Kael'thas of a powerful weapon. These brave adventurers were granted the key to Tempest Keep, and sent to dispatch Kael'thas himself.

Defeated
Prince Kael'thas was ultimately cornered in his reinforced sanctuary of Tempest Keep, The Eye. He was defeated, though the timely arrival of Priestess Delrissa had allowed him to escape death. His image appeared in Shattrath, berating A'dal for not finishing the job with the same efficiency that he had claimed Tempest Keep.


 * emote
 * emote
 * yell
 * yell
 * yell
 * yell
 * yell
 * yell

The Sun King Returns


Despite his defeat in Tempest Keep, Kael'thas survived the ordeal with the aid of Priestess Delrissa and continued to advance the plans of his dark masters. His appearance, however was changed: his skin was sickly pale, and a crystal was lodged in his chest, and one of his Verdant Spheres is gone, having been taken by those who defeated him previously. Having collected the necessary energies from his manaforges in Netherstorm, Kael'thas returned to Quel'Thalas to reinvigorate the Sunwell - not as the source of his people's magic, but rather as the mystic portal that will allow him to summon his new master, Kil'jaeden, much as the Well of Eternity was used to summon Sargeras ten millennia before.

Kael'thas made his return to Quel'Thalas, and briefly assaulted Silvermoon City personally with his felblood elves to retrieve M'uru. The Blood Knight matriarch, Lady Liadrin, witnessed this herself and travelled to Shattrath - renouncing her loyalty to House Sunstrider and offering to fight alongside the Sha'tar for Silvermoon's sake.

Following this, the combined forces of the Scryers and the Aldor formed the Shattered Sun Offensive, dedicated to ending Prince Kael'thas' dark ambitions. Kael'thas took up residence in the Magisters' Terrace, reinforced the isle with his last loyal servitors and Burning Legion assistance, and abducted the mortal avatar of the Sunwell - Anveena, who had been placed under blood elf protection in Quel'Thalas.

Inside the Terrace, heroes assisted by Kalecgos battled their way to the twisted prince's inner sanctum. Kael'thas made his final stand, a shadow of his former self, and was cut down by the Shattered Sun Offensive, who claimed his head. Unlike his final thoughts in Tempest Keep, he did not meet his end with a cry for his homeland upon his lips; but instead wished only a violent death upon his killers.

Legacy
The betrayal of Kael'thas sent shockwaves throughout the Kingdom of Quel'Thalas, and as Kael'thas was the last known member of the Sunstrider dynasty, Regent Lord Lor'themar Theron has become the sole leader of the blood elves. His once noble goals for his people aside, Kael'thas is now reviled as a traitor, who attempted to sell both his people and himself to the Burning Legion. Despite this, the statues of Kael'thas remain within Quel'Thalas and Silvermoon City.

Ironically, Kael'thas' increasingly desperate quest to relieve his people of their addiction would ultimately bear fruit. With the "blessing" of the Burning Legion, his own followers were permitted to gorge themselves on colossal amounts of fel power, thus becoming known as "felblood elves" in the process. His actions in abducting M'uru indirectly led to Prophet Velen using M'uru's "heart" to revitalize the Sunwell - that had been defiled by both the Scourge and Kil'jaeden. As such, Kael'thas' people have the Sunwell returned to them, now a mixture of both arcane and holy power.

Rommath, who was perhaps left the most shattered of all after Kael'thas' betrayal, mentioned that Kael'thas had been buried on Quel'Danas.

Personality
All he feels now is hatred for the undead that ravaged his homeland, rage for the Alliance he feels failed his people, desperation over his people's collective addiction to magic, and grief for his ravaged kingdom. However, he is proficient in siphoning magical energies from demons to feed his addiction and has taught his brethren to do the same. Lately his hunger for magic has clouded his judgment. Kael'thas, though judged and seen as a madman, is merely a misguided leader, who will stop at nothing to save his people, even if that means the slaughter of his former followers and allies.

Crowned?
Kael'thas, as the last known surviving member of the Sunstrider dynasty, is the heir to the high elven crown but has yet to take it. Instead, he styles himself as the "Lord of the blood elves."

There has been speculation as to whether or not Kael'thas was ever officially crowned King of Quel'Thalas. The blood elves in Silvermoon still refer to him as "Prince Kael'thas", as do certain members of his own forces (Ambassador Solannas and Warden Mellichar, to name a few). However, the Burning Crusade brings the question to center stage, with two discoveries in the Draenei starting zones - one in Azuremyst Isle, and one in Bloodmyst Isle.

On Azuremyst Isle, a set of orders were sent to Engineer "Spark" Overgrind, a gnome working with the Venture Co. to steal the Exodar. In discussion with the goblin Geezle, Overgrind asked the Venture camp leader if he knew what Kael'thas did to people who failed him - implying that the gnome envoy was in fact a servitor of Kael'thas. After killing Overgrind, draenei players discover a set of orders given to Overgrind in regards to stealing the Exodar, a component of Tempest Keep, back from the draenei. It makes several mentions of a "Master" and it is signed "King Sunstrider". After Overgrind is confronted with the knowledge that he is a traitor to the Alliance, he cackles and confirms that he is a sleeper agent, asking the player "Does it frighten you to know that there are those that would serve the Legion with such devotion as to remain unwavering citizens of your pointless civilizations until called upon?"

Another indication that Kael'thas officially took the throne is from a Sunhawk missive, found by draenei players on the bodies of blood elf spies in Bloodmyst Isle — translated so that it can be read by the player — before bringing it to Velen in the Exodar. It also mentions a "Master" and is signed by Kael'thas himself. The missive details Kael'thas' plan to send reinforcements to the islands to retake the Exodar and bring it back to Tempest Keep. It begins with "Declaration from the Sun King" and reads in full:


 * Sunhawks - my precious, loyal children - your king commends you. Your presence on Azeroth is of the utmost importance to both myself and the Master.


 * Soon, the sun portal will be ready to transport reinforcements from Tempest Keep directly to Bloodmyst Isle.


 * We will reclaim the Exodar. We will slay the blue skinned mongrels where they stand. Velen will pay for his crimes.


 * -King Kael'thas Sunstrider

The "sun portal" in question is located near the crashed remnants of the Vector Coil in western Bloodmyst.

Aside from his self-styled title, "the Sun King," Kael was only ever referred to as "prince" by others - both his followers and his enemies.

When being scrutinized by Champion Vranesh, Silvermoon City Guardians can sometimes be caught proclaiming "Glory to the Sun King" before quickly catching their slip of the tongue and proclaiming Glory to Silvermoon instead.

However, it is also possible that all the above may simply be due to convention and practicality, as Kael may have automatically become king upon the death of his father but never had an official coronation. This would be comparable to what occurs in many real-life monarchies, such as that of the United Kingdom, where the crown prince/princess immediately assumes the title of king or queen (and is referred to as such) upon the death of the current monarch, but the coronation may not take place for several months or longer--if it even takes place at all. A prime example is Edward VIII, who abdicated only months after becoming king but before his formal coronation, yet is still referred to as king and is listed among the historical monarchs of the UK.

The Frozen Throne

 * For gag quotes see: Quotes of Kael'thas Sunstrider.


 * The Scourge devoured our ancient homeland of Quel'Thalas. The once-proud bloodline of my people is nearly spent. The few of us that remain now call ourselves blood elves, in homage to our murdered people.
 * This is preposterous! Am I to assault the undead with nothing but sticks and harsh language?
 * Arthas: Are you still upset that I stole Jaina from you, Kael?
 * Kael: You've taken everything I've ever cared for, Arthas. Vengeance is all I have left.

Lore

 * When the Flames settle, we shall see who still stands!
 * Lord Illidan awaits!

Icecrown

 * "Pity I wasn't there to stop you. It's been a long time, Arthas."
 * "Arthas Menethil. I would spit at the thought of your name in my mouth, but you aren't even worth that."
 * "You may not care for your subjects, but I care for mine. I have lost far, far too much in dealing with humans. I stand only for the elves now - for the sin'dorei. The children of the blood."
 * "Jaina loathes you now, Arthas. You sicken and disgust her. Anything she felt for you has long since turned into hatred."
 * "You're good at killing noble, elderly men. At least you faced my father on the battlefield. What of your own, Arthas Menethil?"
 * "Felo'melorn is stronger than ever - as am I. As are the sin'dorei. We are stronger for having been broken. Stronger and filled with purpose. And that purpose is to see you fall."

Black Temple Trailer

 * Originally appeared in The Frozen Throne, then repeated (in flashback) in the Black Temple trailer.


 * Illidan Stormrage: Magtheridon lures scores of hapless demons through them daily. Kael'thas Sunstrider: Then we must seal them permanently.

Sunwell Trailer
Kael'thas narrates the trailer for "Fury of the Sunwell", which is patch 2.4.0.

It was called the Sunwell...

''A sacred fount of untold power, it saturated every fiber of our being. In the warmth of its glow, we thrived...until the shadow of death fell upon us.''

''Only after the Sunwell's destruction did we realize how dependent we'd become upon its magic, how much we needed to feed! In the wake of our devastation, I named our people "sin'dorei" - blood elves. My people turned to me for answers. I promised them a cure. Strangely, we found deliverance in the demon Illidan. Illidan offered new sources of arcane power, and so I joined him in Outland - pledging to return one day to lead our people to glory!''

''But Illidan's agenda was short-sighted. I grew impatient. In secret, I began harvesting what energies I could. I had a brief taste of TRUE power...before it was taken from me!''

''But...all is not lost. The Sunwell's essence endured, kept hidden by those who sought to protect it. Now, I have returned with the knowledge that sacrifices must be made before we can reclaim our birthright. I have forged a new alliance. Soon, the blessed rays of the Sunwell will shine once again, and usher into this world the one...who will deliver us all.''

Magister's Terrace
''Don't look so smug! I know what you're thinking, but Tempest Keep was merely a set back. Did you honestly believe I would trust the future to some blind, half-night elf mongrel? Hahahaha... Oh no, no, no, he was merely an instrument, a stepping stone to a much larger plan! It has all led to this...and this time, you will not interfere!''

A much more heated quote is heard upon his death:

''My demise accomplishes nothing! The master will have you! You will drown in your own blood! The world shall burn! Aaaghh!''

The phrase "merely a setback" has become a common utterance by players discussing potential future dungeons and raids, often with the joking implication that Kael'thas will somehow return.

TCG
"Welcome…to the future. A pity you are too late to stop it. No one can stop me now! Selama ashal'anore!"

Notes and trivia

 * He was a wizard and fighter in the Warcraft RPG and was changed to a mage and warrior in the World of Warcraft RPG.
 * His line "Tempest Keep was merely a setback!" has become infamous amongst players, usually using a version of the line for a joke about one antagonist or another returning yet again. This line has subsequently been used by a few other NPCs, including Prince Valanar ("Naxxanar was merely a setback!") in Icecrown Citadel, Hogger ("Forest just setback!") in the Stormwind Stockade, and Crusader Lord Valdelmar {"Undeath is merely a setback!") at Tyr's Hand.
 * Kael'thas is the owner of several verdant spheres, one of which can be obtained by players as a quest starting item.
 * The betrayal of Prince Kael'thas to the Burning Legion was met with mixed reactions, as Kael had seemingly gone from a "well-intentioned leader" to a "pawn of the Burning Legion" with little explanation given for this disconnect. The issue was brought up during the 2010 Blizzcon, where Blizzard stated that a number of years ago Micky Neilson wrote a 80 page long novella explaining the path of Kael'thas. But Blizzard had struggles in finding a way to publish the novella but would like to put it out at some point.
 * Kael'thas once judged the orcs for how poorly they were dealing with their lethargy, cut off from the power that had once sustained them. Ironically, this very fate would later befall Kael'thas and the entire high/blood elven race.
 * Kael'thas is voiced by Quinton Flynn in World of Warcraft: The Burning Crusade and Warcraft III: The Frozen Throne.