Demon! My Firepower Is Greater Than Yours!

At the end of the world war, the military medical captain who was burdened with huge debts was pulled into another war in the dark side of the world by chance. The underground ruins leading to hell, the unknown powerful contract, the horrific rituals that transform humans into supernatural demons, and the deformed creatures born from the collision of technology and magic made Joshua, the man who was forced to guard the gate of hell, start to think. And when countless ancestors who had turned into demons were about to climb out of the gates of hell and return to the world to cause trouble, Joshua glanced at a pile of arms not far away that had been eliminated by various forces after the world war. Ever since, the original mysterious story began to undergo a strange change. Demon Lord: "Stupid humans, why don't you use magic to deal with us? Bullets are as good as tickling me when I was a human magician!" "Boom!!! Boom!! Boom!" (A dull explosion from a distance) # Demonlord looked up in confusion #The demon army's tragic howl Demon Lord: "No, buddy? Why is there a meteor shower in hell?" Joshua: "Oh, that's not a meteor shower. That's a 75mm field gun I bought at a low price. There are only a dozen of them." In this way, a genius magician who is proficient in large-caliber physical magic was born. (Ruins Exploration) + (Contract Demon) + (Farming) + (No System, No Time Travel)