Alicization

Alicization is a major story arc in the Japanese light novel series Sword Art Online, written by Reki Kawahara. It is the third major arc of the series and the first to be adapted into anime. The story takes place in the virtual world of the Underworld, a highly advanced simulation created by Rath, a government-funded research institute.

The protagonist, Kazuto Kirigaya, also known as Kirito, finds himself trapped in the Underworld without his memories or a way to log out. He awakens as a young boy in the village of Rulid and is taken in by a blacksmith named Eugeo. Together, they embark on a journey to find Alice Zuberg, a childhood friend of Eugeo's who was taken away by the Axiom Church for breaking the Taboo Index.

The Underworld is governed by a complex system of rules and a powerful entity known as the Administrator. Kirito and Eugeo must navigate this world, battling powerful knights and facing moral dilemmas as they uncover the true nature of the Underworld and Rath's intentions. The arc explores themes of artificial intelligence, consciousness, and the definition of humanity. It is known for its extensive world-building, character development, and emotional depth, and it significantly expands the lore of the Sword Art Online universe.