Arifureta: From Commonplace to World’s Strongest: Volume 5 oleh Ryo Shirakome

With the addition of Kaori into their party, Hajime and his friends make for Myu's hometown, the coastal city of Erisen. While crossing the Gruen Desert, they save a young Ankajian man, Bize, from a sandworm attack. Apparently, he was searching for a cure to the mysterious disease that has struck his people. His travels led him to conclude that a mineral known as stillrock held the key to saving his country, but it can only be found inside the Grand Gruen Volcano, a labyrinth far too dangerous for most. Hajime agrees to help Bize procure some, and the party begins their quest to conquer yet another labyrinth. But along the way, they meet a most unexpected foe...