Official_Ozora11
Sword Art Online Alicization and Sword Art Online War of Underworld follow Kazuto Kirigaya as he becomes involved with RATH and their secret Project Alicization, which uses the Soul Translator (STL) to interact directly with the human Fluctlight, or soul, in an attempt to create true artificial intelligence through a massive virtual world known as the Underworld. After suffering severe brain damage in the real world, Kirito is placed inside the Underworld to recover, where he befriends Eugeo and fights alongside him to rescue Alice Zuberg while uncovering the truth behind the Axiom Church and its ruler, Administrator. At the same time, following the events of Sword Art Online The Movie: Ordinal Scale, Yasinel remains hospitalized after suffering catastrophic fluctlight trauma during the Augma incident, losing most of his memories and undergoing neurological rehabilitation under the supervision of Rath and Rinko Koujiro, whose connection to Akihiko Kayaba and knowledge of Heathcliff's relationship with Yasinel help slowly guide his recovery. After Eugeo's death and Kirito's mental collapse during an attack on Rath's Ocean Turtle facility, the Underworld falls into chaos as the Dark Territory launches a massive invasion led by Gabriel Miller, who manipulates players from around the world into joining the conflict. Asuna, Sinon, and Leafa enter the Underworld using Rath's goddess super accounts, while Yasinel, having partially recovered his identity and memories through Rinko's STL-assisted rehabilitation at the hospital, logs in from there using a specialized high-authority account known as Ignis, a flame-based super account tied to large-scale combat and fluctlight synchronization.