The Demon Sword Master of Excalibur Academy, Vol. 10 (light novel‪)‬

THE SECRET OF THEVOID WORLDAn attack by the Queen of Shadows has left Leonis and Riselia in the Voids’ home dimension. However, rather than join Princess Chatres with the other abductees and return to Camelot, they decide to explore, hoping to find some clue about the origin of humanity’s greatest enemies. Their search brings them to an abandoned kingdom Leonis recognizes. But how could that be? This is supposed to be an entirely different world…