Sword Art Online Progressive 9 (light novel)

Secrets of the lake revealed!When clearing the seventh floor, Kirito transforms into a Civis Nocte, kindred to vampires, and receives great power in exchange for a lethal weakness to sunlight. With Asuna and Kizmel, he pursues the Fallen Elves who have stolen the five sacred keys at the center of the "Elf War" campaign questline. To the group's surprise, however, their search ends up taking them back to the fourth floor. There, Kirito and company accept a request from Lavik, the former commander of the Sandalwood Knights Brigade. In doing so, they become embroiled in an ancient dispute among the elven peoples and delve into the past of Viscount Yofilis. Amid all this drama, one thing is for certain: No one can call the NPCs simple AI anymore!