The final load test… The war between the Human Empire and the Dark Territory has engulfed Underworld entirely. The battle has shifted course with the Dark Territory army led by Gabriel, who seeks to capture Alice, the Priestess of Light, against Asuna and the Human Empire forces fighting to save Underworld.

As Kirito’s consciousness remains buried in a deep sleep, Gabriel, standing in as the Dark God Vecta, has recruited thousands of American players to log in to Underworld to annihilate the Human Empire forces. Meanwhile, Asuna, Sinon, and Leafa have joined the battle utilizing three super-accounts of the deities of the Underworld. As the Goddess of Creation Stacia, Asuna fights alongside the Human Empire forces to take on the American players in a vicious combat.

Sinon, who has gained the super-account for the Sun Goddess Solus, is in pursuit of Gabriel, who has abducted Alice, while Leafa arrives to Underworld with the super-account Earth Goddess Terraria. But that is not all…

The impassioned speech by Lisbeth has convinced many ALO players to join the fight with the Human Empire despite the risks. With this great war, not only Underworld’s continued existence, but the bottom-up artificial intelligence, the ultimate AI, and even the future of mankind is at stake. Though he has yet to awaken, only one man holds the fate of this world: the Black Swordsman.

"And so the grand finale of the Alicization arc begins…"

[Source: official English website]