Saikyou F-Rank Boukensha no Kimama na Henkyou Seikatsu?

"Lumen, a remote city at the edge of the dreaded magical borderlands, is a dangerous place for any adventurer. Roy, a newly minted F-ranked adventurer, arrives on a whim, seemingly unprepared for the monster-filled outpost. But surprisingly, he’s actually a top-tier swordsman and mage! This outclassed 'novice' shakes up the city—and the entire world—with his unexpected power!"