post-apocalypse I can turn anything in to a weapon

Ren Kisaragi, a reclusive gamer, is suddenly thrust into an apocalyptic world after a meteor strikes Earth. With no weapons at hand, he discovers he’s been granted a unique class: Itemless Champion. Using his creativity, Ren can turn everyday objects into powerful weapons, but each transformation costs precious mana. As monsters invade the world, Ren must navigate this new reality, fighting for survival while uncovering the truth behind the meteor and his newfound abilities. Will his gaming instincts be enough to help him conquer the apocalypse, or will he fall victim to the chaos.