Sword Art Online: Alicization - War of Underworld is a tV series anime that premiered in fall 2019, produced by A-1 Pictures.

About the production: the story comes from a light novel, there are 12 episodes of about 24 minutes and its current status is "finished".

Its main genres are action, adventure, drama, fantasy and sci-fi, with themes such as Virtual World, Swordplay, Artificial Intelligence and Video Games.

On AniList, Sword Art Online: Alicization - War of Underworld has an average score of 75%, a very good score, and appears on 224,960 users' lists.

The franchise continues in or follows from: Sword Art Online: Alicization and Sword Art Online: Alicization - War of Underworld Part 2.

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. 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... (Source: Official Website)

Official synopsis from AniList.