Sword Art Online: Alicization will be returning for the second half of the third season in just a few days from now, and fans now know where they will be able to see what's to come from the War of Underworld arc as Crunchyroll has confirmed that they will be streaming the new episodes alongside its debut in Japan beginning on October 12th at 9:30 AM PT. The War of Underworld segment of the series continues the story from the longest arc of the original light novel series to date, and will see a more intense world when fans return to the third season.
It's been confirmed that the new War of Underworld segment of the third season will be split into two separate parts. While this confirms earlier reports that the Alicization arc of the series would be running for four cours of episodes in total, this means fans will have to wait a bit longer to see how it all concludes.
But in that same breath, the third season has been one of the best received seasons of the series thus far and more time devoted to how it all ends can only be a good thing. Crunchyroll's announcement also comes with a new synopsis, too, and they describe Sword Art Online: Alicization - War of Underworld as such, "Kirito, Eugeo, and Alice. Six months have passed since the two disciples and an Integrity Knight brought down the pontifex, Administrator. With the fighting over, Alice has been living in her hometown of Rulid Village. Beside her is Kirito, who has not only lost his arm and soul, but also his dear friend.
As Alice devotes herself to looking after Kirito, she too has lost the will to fight she once had as a knight. "Tell me, Kirito… What should I do?" Nevertheless, the time for the final stress test – one which will engulf the entire Underworld with tragedy – draws relentlessly closer. Meanwhile, in the deepest areas of the Dark Territory, the Dark God Vecta has resurrected, as if to have waited for this very moment. Leading an army of dark forces, they begin their invasion into the human empire in hopes of attaining the Priestess of Light.
The human empire force led by the Integrity Knight Bercouli prepares for a war of an unimaginable scale against the army of the Dark Territory. Even then, Alice is nowhere to be seen, nor the two heroes that saved the realm… The curtain rises on the final chapter of the SAO series' longest and most glorious battle – the Alicization arc."