I Am the Great, Great, Great Demon King

My name is Mo Wangjun. Everyone who knows me calls me the "Great Demon King," not because I was born with a condition called "shark teeth," nor because I was born with a demon king's face, nor because my physical abilities are freakishly strong, nor because I'm a naturally cruel and heartless villain. It's because my name is literally "Mo Wang [Demon King]." What? You think that's ridiculous? I guess it is a little... All right, maybe more than a little. But from now on, you can't call me the "Great Demon King" when we fight! You have to call me the "Greatest Demon King"! Why? Because... my chest is now almost a hundred meters tall!!!