Avatar of Sargeras

The Avatar of Sargeras was a physical shell hosting a portion of the soul of the Lord of the Burning Legion, Sargeras, who battled the second-to-last Guardian of Tirisfal, Aegwynn, in the wastes of the Dragonblight roughly 823 BDP. Though only a tiny fragment of Sargeras' true form and devastating cosmic power, the Avatar radiated great strength and fury, and was so large as to rival the bones of the gargantuan proto-dragon Galakrond in stature. After Aegwynn defeated the Avatar, she buried it deep within the Tomb of Sargeras.

Creation of the Scepter
Following the War of the Ancients and Sargeras' first, failed attempt to enter the world of Azeroth, the Dark Titan immediately began planning his next method of infiltrating the planet. He knew that he couldn't rely on a static portal since such a gateway would require an astronomical amount of power to serve a titan, and the most promising source — the Well of Eternity — had been destroyed in his last attempt. Additionally, the Highborne's laborious preparations had given away his intentions, allowing the night elf resistance to thwart him. Sargeras concluded that he instead needed to enter the world with minimal warning. He commanded the eredar to create a tool that could temporarily wrench open rifts between worlds, just long enough to let a portion of his soul through. Although that meant he couldn't enter Azeroth in his most devastating form, such an instrument would clear a path for his avatar to lead the Legion's invasion or carry out subtler schemes. The weapon would also weaken and threaten to collapse the physical universe, but Sargeras considered those to be only side benefits.

The result of the eredar sorcerers' monstrous undertaking was the Jeweled Scepter of Sargeras, which would allow Sargeras to create portals to any realm he desired, but the rifts it created would only allow a portion of his soul to enter. Sargeras would simply have to be more creative with his plans, and so, he waited. Millennia later, he found his opportunity in the form of Aegwynn, the then-Guardian of Tirisfal. She had become the most powerful mage on Azeroth, beyond even the Council of Tirisfal's ability to control, and her pride made her a fine candidate for corruption.

The clash with Aegwynn
Around the year 823 BDP, Aegwynn had traveled to the Dragonblight to aid the dragonflights in banishing a pack of demons that were draining the potent arcane energies of the blue dragons. Just as the last demon was banished from the world, the sky turned black and a massive, dreadful sound, "like that of a mace splitting a giant's skull", echoed across the wastes as the Avatar of Sargeras entered the battle. He informed the young Guardian that the time of Tirisfal was about to come to an end and that the world would soon bow before the onslaught of the Burning Legion. Aegwynn raised her staff, Aluneth, to unleash a storm of arcane magic, but nothing happened. Realizing that the entity within the staff was resisting her commands, Aegwynn instead summoned the greatstaff Atiesh to aid her in battle. The following battle was the most difficult Aegwynn had ever fought. As the Avatar and the Guardian clashed, a storm of magic engulfed the region, holding even the mighty dragons at bay, but Aegwynn finally defeated her opponent with a final flurry of arcane might.

However, at the time of the Avatar's death, Sargeras had transferred a portion of his spirit into Aegwynn's soul. The Guardian herself was unaware of this and dismissed the hollowness she felt inside her as being caused by the strain of the battle. Even in death, the Avatar's corpse was malevolent, still gripping its massive scepter, and Aegwynn resolved that she could not allow it to rest next to Galakrond's bones. She considered many locations to serve as the demon lord's final resting place, but finally chose a sunken, ruined portion of the ancient night elf city of Suramar, which had been secured with Highborne seals that would nullify any evil that still lingered in the Avatar's body and the scepter it wielded. The building where the Avatar was interred, once called the Temple of Elune, would eventually become known as the Tomb of Sargeras. Aegwynn also imprisoned several of Sargeras' demon followers alongside the Avatar. Most of them were dead or barely alive, and the Guardian believed that the tomb's enchanted seals would keep them contained. While it was true that the demons would never have been able to escape the structure on their own, over the millennia some of them fed on the Avatar's lingering power and regained enough strength to prowl the tomb.

Meanwhile, Sargeras' spirit lingered within the Guardian, darkening her thoughts and driving her to distance herself even further from the Council of Tirisfal, until many years later it passed from Aegwynn to her son, Medivh.

Legionfall


With the Legion tearing down the tomb's barriers, Kil'jaeden is in a position to reanimate the Avatar of Sargeras and unleash its power on Azeroth. The fallen husk of the Avatar remains in the lowest, deepest recesses of the Tomb. A remnant of Sargeras' dark power lingers within the construct, and adventurers will need to defeat it in order to accomplish their goal in the depths of the Tomb. The Fallen Avatar thus serves as the penultimate boss in the Tomb of Sargeras raid.

In the RPG
The avatar of Sargeras is an incarnation of the lord of the Burning Legion believed to be created from part of Sargeras' spirit. The second time that Sargeras entered Azeroth was in the form of an avatar. Aegwynn, the Guardian of Tirisfal at the time, detected Sargeras's presence, hunted his avatar down and defeated it in combat. She "destroyed" the avatar with a single spell, or so she thought — in reality, Sargeras just implanted himself inside her womb, ensuring that the next Guardian would contain his demonic essence.

Many believe that Sargeras's spirit yet endures, somewhere — hungering for revenge against the only world ever to withstand the Burning Legion's might... Some people think the Avatar was the real Sargeras, but Brann Bronzebeard is pretty confident he never actually set foot on Azeroth.