Souma Shirahane and Mutsugi finally reach the Gate of Destruction. There, they saw the changed form of Godou Shirahane, the Light Slash Knight Zango who had hardened into a Lost Soul Beast form and was holding the Gate of Destruction in his arms. Mutsugi's expression turns cold in front of the shocked Souma... Meanwhile, Ryuga Dougai and Koyori, who have been transported to another space, are suspicious for Mutsugi's actions in the labyrinth Arivis. What is Mutsugi's true intention?