"You are not prepared!"
Illidan Stormrage was a night elf demon hunter. Over the course of his long life he's held many different careers, including mage, double agent, prisoner, demon, attempted saviour, and despot.
Born over ten thousand years ago, Illidan lived during the height of the night elf civilization. From a young age, Illidan was fascinated by the magic of the Highborne night elves, and wanted nothing more than learn and master that power. Despite his status as a commoner, Illidan was able to learn and control the magic of the Well of Eternity, with considerable aptitude. Although many of the Highborne did not take him seriously as a mage, Lord Ravencrest, recognized his talent and took him on as his personal mage. Meanwhile, his brother Furion, a self-proclaimed scholar and hippie, won the heart of Tyrande, the love of their lives, who was not impressed at all by the amazing acts of magic Illidan could do.
It was soon clear that something was rotten in the heart of Zin-Azshari. A darkness seemed to have overcome the Highborne, and rumours of terrible monsters lurking about spread until an entire legion of them appeared, taking control of the capital. Illidan was quick to leave the ranks of the Highborne and joined his brother in the night elf resistance. They fought together, gathering allies, in a desperate effort to drive the demonic invaders back to whence they came. It soon became clear to both of them, however, that there was no hope that the night elves and their allies would be able to defeat the seemingly limitless numbers of the Burning Legion. Both recognized that the massive demonic portal empowered by the Well of Eternity needed to be shut down and sealed, however, the two brothers disagreed on exactly how to go about doing that. Furion advocated that the best course of action would be to destroy the Well of Eternity, as he believed that the arcane power of the Well had been the cause of the corruption. Illidan, however, strongly disagreed, as the Well of Eternity was the source of his arcane power, and the immortality of the night elves. When Furion was successful in convincing their allies to launch an assault on the Well of Eternity to destroy it, Illidan left to enact his own plans to seal the portal. Of course, to have the time to enact his plan he needed to sell out his brother and his allies in order to prevent them from destroying the Well of Eternity. This made him very unpopular with his brother, and his allies.
"I will be the savior of our people! I WILL FULFILL MY DESTINY!"
However, while he had fallen out of favour with his former allies, Queen Azshara and her demonic allies were pleased with his service. Sargeras himself rewarded him by burning out his eyes, replacing them with a pair of mystical orbs which gave him to ability to see magic, and awesome magical tattoos.
When the time came, Furion led his forces into the heart of Zin-Azshari to face Azshara and the Burning Legion. They stormed the palace, and Illidan did his part to help the invaders. Illidan sealed the portals, stemming the flow of Legion reinforcements, and helping the rebel night elves where he could. Abandoning Furion, and Azshara to their battle, he rushed to the Well of Eternity where he filled seven specially prepared flasks to contain its waters. Despite Illidan's efforts to preserve the Well, Furion's battle with Azshara and her minions disrupted the remaining portals, which in turn destabilized the Well of Eternity. Despite successfully driving back the Burning Legion, the Well of Eternity was about to explode, and would likely take most of the night elves' empire with it. Illidan, Furion, Tyrande, and their surviving allies fled the city, leaving Azshara and the remaining Highborne to their fate.
The Well of Eternity exploded, ripping apart continents, and sinking vast landmasses in the process. The bulk of the Highborne were presumed drowned along with their queen. The world had been saved from the Burning Legion, but at a terrible cost. Illidan made a long trek to the top of Mount Hyjal, where he found a small lake. Pouring the contents of three of his vials into it, he attempted to create a new Well of Eternity. Illidan had expected that Furion and their people would be happy to learn of his wonderful new creation, that he had managed to preserve the Well of Eternity and its power for all their people. However, the survivors, having survived a demonic invasion, having their empire sink beneath the waves, and seeing the world ripped asunder, had lost their enthusiasm for magic. In fact, most of them blamed the reckless use of arcane magic, and the power of the Well of Eternity, for the entire fiasco. Confused by this turn of events, Illidan tried to argue that magic would be necessary to defeat the Burning Legion should they ever return, but the angry night elves would hear nothing of it. Furion sentenced Illidan to be imprisoned indefinitely, and he was locked away underground, somewhere on Mount Hyjal. Before he was locked away, however, Illidan managed to slip one of his vials of Well of Eternity Water to
Dath'Remar Sunstrider who would later use it to help create the Sunwell in Quel'thalas, and somehow train several other night elves to be Demon Hunters.
Illidan then proceed to spend the next ten thousand years locked in a cell deep beneath the earth, under the watchful eyes of the Wardens and
Maiev Shadowsong. When the Burning Legion returned, Tyrande decided that Illidan's help in the crisis would be useful, and sought to free him from his prison. The Wardens strongly opposed this, and so Tyrande was forced to fight her way through them and release Illidan without their consent. Illidan, happy to be free for the first time in ten thousand years, and was glad to lend his aid against the Burning Legion once again. Furion, however, was quite upset about Tyrande's actions, and was very unhappy to see his brother out of his cell. Illidan stormed off, outraged once again at his brother, and looked for a way to prove that he wasn't the power obsessed magic addict his brother thought he was.
Maiev returned to the barrows sometime later, having taken her first break in ten thousand years. Horrified that Illidan had escaped, she swore she'd never take a break again, and would hunt Illidan to the ends of Azeroth and bring him back in chains.
"I am free after ten thousand years, yet still my own brother thinks I am a villain! I'll show him my true power! I'll show him that the demons have no hold over me!"
When travelling through Felwood, Illidan encountered an agent of the Lich King, the death knight, Arthas. Arthas tipped Illidan off to the source of the corruption in the forest, the Skull of Gul'dan, and left the demon hunter to sort things out. Illidan did so, setting out to destroy the Skull of Gul'dan and defeat the demon, Tichondrius, who had taken up residence in the forest. Along the way, however, he realized that if he claimed the power of the Skull for himself, he'd have more than enough power to dispatch the dread lord, and still stop the corruption of the forest. Illidan did so, transforming himself into a demon, and then promptly dispatching Tichondrius with his new power.
"Now I am complete!"
In retrospect, maybe absorbing the power of a demonic artifact and transforming himself into a demon was not the best way to prove to his brother that he wasn't a power obsessed magic addict. Despite having destroyed one of
Archimonde's lieutenants, and halting the corruption of Felwood, his ungrateful brother was still upset at him, and exiled Illidan. Illidan, although upset, was accepting of this, because it was still better than going back into a dark hole in the ground. Leaving Furion, Tyrande, and night elves on their own, he left.
Archimonde was defeated without his help, and the surviving Legion forces were left in disarray. Illidan travelled on his own through Kalimdor for a time, until he found himself contacted by the demon lord, Kil'jaeden. Kil'jaeden, upset at the Lich King's treachery, needed an agent to dispose of the undead menace, and offered Illidan more demonic power if he'd deal with the Lich King for him. Illidan, quick to jump on any chance to be a hero and acquire more power, accepted. Gathering up some satyrs as allies, he set out for the coast where he was able to call on some of his other old allies, the highborne night elves who had long since been transformed into naga.
Lady Vashj answered his call, and together they travelled to the Broken Isles, where they entered the Tomb of Sargeras. Using Gul'dan's memories, they were able to navigate the dungeon, and locate what the orc warlock had long sought: the Eye of Sargares. Using the power of the Eye, Illidan hoped to shatter the Icecrown glacier, and destroy the Frozen Throne without risking a direct confrontation with the Scourge. Unfortunately, Maiev arrived and attempted to stop him from claiming the Eyel. Illidan and his allies retreated, but not before Illidan used the Eye to bring down the tomb, in an effort to trap Maiev there. Maiev was able to escape the Tomb, but not without abandoning her friends and allies.
Illidan fled to the ruins of Dalaran, where he prepared his ritual to destroy Icecrown glacier and the Lich King. This time, he was interrupted by Malfurion. The two argued briefly about the ethics of Illidan's spell casting, Malfurion citing that the spell was threatening to rip the continent of Northrend apart, and Illidan pointing that he was trying to kill the Lich King and end the Scourge, the common enemy of all living creatures. The argument ended when Malfurion revealed that Maiev had told him that Tyrande had been killed and devoured by the Scourge while they were helping
Kael'thas. Illidan was momentarily sullen, but then Kael'thas piped up and told them that no such thing had happened, she'd merely been swept down river. The two brothers agreed to set aside their differences and save Tyrande before Maiev's lie became the truth. Joining their forces together, Illidan and Malfurion saved Tyrande, and finally forgave each other. Setting aside their differences at long last, Illidan left Azeroth, opening a portal to Outland in an effort to find a place to hide from Kil'jaeden who would no doubt be angry at his failure to uphold his end of their bargain. Maiev followed him.
In time, Vashj and Kael'thas joined him in Outland, rescuing him from Maiev who had managed to catch him and put him in a cage. Together, they rallied some of the draenei survivors, led by the Elder Sage, Akama, and overthrew
Magtheridon, who had been ruling Outland from the ruins of the Black Temple. With Magtheridon defeated, Illidan declared himself Lord of Outland, and with his new allies, they all prepared to settle in to their new abode when Kil'jaeden showed up.
Kil'jaeden, upset that the Lich King still was not dead, reminded Illidan of his bargain. Noticing that Illidan had managed to rally a fairly impressive army, Kil'jaeden decided to give Illidan one more chance to not earn his eternal ire. Message received, Illidan and his allies prepared to march on Icecrown and destroy the Lich King.
It could have gone better. Illidan was defeated at Arthas' hands, and left for dead in the snow. His allies were able to retrieve him, and together they retreated back to the questionable safety of Outland. Illidan began making preparations for the inevitable arrival of Kil'jaeden's wrath, and sought to further secure his dominion over Outland.
"Alas, poor Yorick!"
During this time, he managed to train a new cadre of demon hunters, create a font of pure arcane energy capable of relieving one of the effects of magic addiction, anger the naaru and their allies (causing them to wage war against each other despite having a common enemy in the Burning Legion), capture and lock up Maiev in return for keeping him in a cage for so long, create an army of fel orcs, enslave the netherwing dragons to serve as mounts for his fel orcs, and possibly go mad.
Despite Illidan's ever increasing paranoia, he somehow missed that two of his once closest allies, Prince Kael'thas and Akama, were conspiring against him. While Kael'thas merely defected to the Burning Legion, Akama was actively plotting to kill him and end his reign as Lord of Outland. With the help from adventurers, Akama put his plan into motion. First by retrieving the
part of his soul that Illidan had taken to ensure his loyalty, and then by helping adventurers fight their way through the Black Temple, and killing Illidan with the help of the adventurers and Maiev. Illidan was killed, and Maiev claimed his corpse as her part of the loot, taking it back with her to Azeroth, sealing it, along with Illidan's soul, back in the barrows to continue to serve out his indefinite life sentence. The adventurers looted whatever magical items Illidan had on him at the time, including his warglaives and the Skull of Gul'dan.
Illidan will be back in some form in Legion. Having trained the new demon hunters, he'll likely be playing a prominent role in their starting area. His motives and goals during the BC-era will be explored in some depth. Additionally, it's been revealed that alternate universe Gul'dan intends to free Illidan from his prison and revive him for whatever reason. Maybe he expects to be friends since Illidan absorbed the memories and power of his main universe counterpart, or maybe he figures he can extract that power from Illidan and claim it for himself, since it was his, sorta.