Review Detail of ThePanzerWaffle in I am the Magicless Demon Lord

How will the MC become overpowered if he relies on weapons?.. Rather, shouldn't he become overpowered by improving himself?I get the theme of the novel, but i don't see how the tag fits if he depends on external elements while being a mortal with limited lifespan himself, and no power.Just curious since i honestly dislike military themes when i believe that a warrior with a sword is stronger than guns in magic worlds.