The Protagonist of the Mutated Modern Era Is a God and Demon

The earth in the parallel world was originally a peaceful land full of vitality. Human beings lived peacefully on this peaceful land. But suddenly one day, those creatures that originally only existed in legends all appeared in the world. They regarded humans as sworn enemies. They wanted to occupy human territory and exterminate all humans. Humans therefore started a war to protect their homes. However, the good times did not last long. The battles were of little use except turning their own territories into desolate ruins. "The weather is really nice today. What? Fighting? Demon hunting? I'm overthinking it. I, Kiragichi... Am wrong. I just want to be an ordinary person. I can just leave fighting to young people." In this world occupied by beings that only exist in myths and stories, what is the protagonist's plan? Are you going to retire and wait for death? Still vigorous... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.