Sortiliena Serlut (ソルティリーナ・セルルト, Sorutirīna Seruruto?) is the mentor of Kirito during his first year in the «North Centoria Imperial Sword Mastery Academy», and the second-seat elite swordswoman at the Academy, where she is known as the Walking Tactics Manual (歩く戦術総覧, Aruku Senjutsu Souran?).