The Strongest Sage with the Weakest Crest 23

After the fierce battle with the abominations, Matty and his friends make a stunning discovery. Hidden underground, someone has constructed a complex artifact that affects the entire world. Even more intriguing is the magic signature that identifies the artifact's creator as a being who possesses both human and demon energy! Despite the fact that this creator has been seemingly dormant for ages, Matty decides that confrontation is the best choice!

Volume 23 of The Strongest Sage with the Weakest Crest manga series by Shinkoshoto.