Sono Bouken-sha, Toriatsukai chuui.: Shoutai wa Muteki no Geboku-tachi wo Suberu Isekai Saikyou no Madou-ou

Synopsis

Is this rookie adventurer one who knows the world? The King of the Sky Castle finally descends! A fantasy about an adventurer who is transported to a game world and changes it! (Source: Kadokawa)