Cardinal

卡迪娜爾 カーディナル

A girl who claims to be the adjustment program of "The Seed" that helped Kirito and his friends. Her true identity is a subprocess of the Cardinal System fused with the Administrator, acting under the command to "correct the mistakes of the main process." In the past, she could only control her body when the Administrator's emotions were disturbed. However, when the Administrator chose a new body to escape the lifespan of her soul, the girl, Lyserith, had her Fluctlight overwritten with the soul of the subprocess, thus acquiring that body. Immediately after, she attempted to forcibly delete the Administrator but failed, leading her to retreat and isolate herself in the Great Library within the Cathedral, devising countermeasures against the Administrator for 200 years in human world time. During this time, she noticed Kirito reappearing in the Underworld with a damaged Fluctlight and assisted his journey through her spider familiar, Charlotte (voiced by Yoko Honna). When Kirito and Eugeo attempted to escape from the Cathedral, she revealed to Kirito that the final load experiment was imminent and that if they defeated the Administrator and reclaimed control, she intended to reset the Underworld along with all existing artificial Fluctlights. She entrusted Kirito with a plan and sent him to confront the Administrator. When Kirito, Eugeo, and Alice faced the Administrator, she also went to the battlefield but was struck by her weakness of "only being able to attack the Administrator," which was exploited in the form of a Sword Golem. In despair, she took a fatal blow in exchange for sparing Kirito and his friends. As she vanished, she heard Eugeo's resolve and transformed him into a sword of the same nature as the Sword Golem.