Are we talking about Amaimon from Ao no Exorcist? (Blue Exorcist) If so, this is how I made mine: I used Simplicity pattern 4083 with minor alterations. In the pattern, the coat is divided in "upper" and "lower" halves -- I just taped those pieces together since I didn't want that weird horizontal seam.I didn't line the coat. Instead of the long sleeves on the pattern, I made short sleeves. I made the lapels look normal sized, and made the collar jumbo sized. (Be sure to use interfacing for the collar. It'll need to stand up.) Since I didn't line the coat, I finished the seams and edges. Once I did all of that... I took a lighter to the jacket bottom. :> It was fun. If you use a lighter to distress the jacket, practice safety. The fabric I used wasn't synthetic, so I had to go over the spots with FrayCheck. If you use something like polyester (which I wouldn't suggest, but still), then there would be no need for the FrayCheck.
Hope that helps.