The Demon King Can't Defeat the Hero, Is It My Goblin's Fault?

[Light novel+anime derivative+different world continent+dungeon+brave+demon king] The Demon King cannot defeat the Hero, so what does it have to do with the Goblin throwing the spear at me? Oh, now you know that I am also the Demon King? Five years! Five years! Do you know how I spent the past five years in the underground city? ... ... Okay, stop talking now, let the red female dragon come over... I want to spank her! Seven brave men and six demon kings gather together, and the fateful battle is about to begin. (A brave man may not be righteous, but the devil must be dark. The content is very simple, a story about a group of people competing against each other.)