You've Got to Be Kidding Me, I'm a Level 999 Commoner

On a continent where humans and demons coexist, countless powerful, terrifying, and savage monsters threaten humanity’s safety and survival. It is said that monsters are drawn by demonic power, and that exterminating all the demons would wipe out every monster. The level-500 Demon King is the most dangerous blade hanging over humanity’s head. For world peace and the survival of humankind, Claude, a level-88 hero, took up the banner of defeating the Demon King… But what’s with the level-999 civilian? This book is also known as My Disciple Is a Hero and How to Reach Level 999.