In the Land of Leadale, Vol. 5 (light novel)  (English, Paperback, Ceez Ceez)

One day, Cayna receives an urgent correspondence from Shining Saber, afellow Leadale player also transported to this new world. It turns out that ahorde of monsters is headed for the royal capital, and he needs Cayna to lendher mighty powers to stop the beasts. But when a Guardian Tower in the form of agiant tortoise appears in Cayna's absence, will Exis and Quolke have whatit takes to handle it themselves?!