Fastest Demon Lord Extermination in History

King: Oh great hero, please defeat the demon lord and save the world! Ok now we’re going to check your abilities using this magic ball. Hero: Nice I got the atom split ability. King: ... what’s that sounds boring Hero: Ima defeat the demon lord right now! ATOM SPLIT EVERY ATOM MODE! ... ... ... KABOOOOOOOOOOM ... ... ... ... And that was how the world ended