Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled.
Sortiliena Serlut (ソルティリーナ・セルルト,Sorutirīna Seruruto?) is the mentor of Kirito during his 1st year in the «North Centoria Imperial Sword Mastery Academy», and the 2nd-seat elite swordswoman at the Academy, where she is known as the Walking Tactics Manual (歩く戦術総覧,Aruku Senjutsu Souran?).
Sortiliena has very long[citation needed], straight[citation needed], dark brown[1] hair and navy blue eyes that are like the sky that was fading into twilight. As an elite-swordswoman, she wore a neat, purple jacket and a long-swaying, purple long skirt.[1]
One day, Sortiliena was doing late practicing with her valet, Kirito, and they talked briefly about how much Kirito had improved since he enrolled. After a while, they stopped and Kirito told her that he wanted to show her his true ability, so he promised that the next day, as a graduation present, he would show her his true skills.
The next day Sortiliena found out that Kirito was with Uolo Levanteinn. When she caught up with them, she was told that they were going to spar as a punishment for Kirito. As she was unable to do anything to stop the sparring, she wished luck to Kirito and just watched the match. After the battle, she congratulated Kirito for his performance against Uolo, and invited him, along with Eugeo and Gorgolosso Baltoh, to her room to celebrate.
During the last tournament before the graduation, Sortiliena finally defeated Uolo by having her Secret Move «Whirling Current» pushed back by Uolo's skill to its pre-motion stance, causing the skill to re-activate and deal a second hit. This was a technique that she mastered in just half a month after seeing Kirito's battle with Uolo. By defeating Uolo, Sortiliena graduated as the top student from the «North Centoria Imperial Sword Mastery Academy». Two weeks after graduating, she participated in the «Empire Swordsmanship Tournament», but lost against a Norlangarth Knight who cut her whip and sent her sword flying. It was later revealed that the Knight who defeated her was Eldrie Woolsburg.