The Strongest Sage with the Weakest Crest 28

ONE BOY WILL STOP AT NOTHING TO BE THE WORLD'S STRONGEST…NOT EVEN USING A DRAGON TO TOW A BOULDER! After completing the transcendent sword, Matty takes his crew to undergo training. Though the newly forged sword is sure to be useful in fighting space monsters, it is also decidedly user unfriendly, so Matty must take some time to figure out how best to wield it. Unfortunately, the training is interrupted by a mysterious bandit who suddenly appears and challenges Matthias to a duel!

Volume 28 of The Strongest Sage with the Weakest Crest manga series by Shinkoshoto.