In my search for power, I was unlucky to find myself in a place that can only be called the Underworld. Scorched earth, a scorching scarlet sun and hordes of demonic spawn. How can an aristocrat expelled from his family survive in such a place? Certainly! Especially if he discovers the power to devour demons and thereby increase his strength. A hundred years later, I became the strongest creature in this world and was able to return to Earth, finding myself in the body of a half-dead teenager. A hopeless situation at first glance, but although... My power as a devourer is still with me, which means I will devour this entire world like the Underworld itself!