I'm looking for this manga..?

I read this manga a long time ago and I forgot what its name was. Well anyway, the story I remember is about how this country is ruled by 12 people with 12 powerful swords. The main character is some guy who has the 13th sword which is the sword of fire. I remember reading the chapter where he beats a guy who had the sword of shadow. If anyone knows what I'm talking about, can you tell me what's the manga's name?