I read this book too after a friend recommended it to me. I thought it was very good for a debut novel. It is by Sam Enthoven and it's about this ancient demon named the Scourge and trying to wake this ancient dragon, the creator of everything. He wants to wake the dragon to bring the world into utter and everlasting darkness. Now, there are these people who have been training to destroy the Scourge and they are plunged into this adventure. They go and try to find it but it inhabits someone. When it inhabits someone it forms as this living tattoo on that persons body. So they travel between Hell and the earth searching for it but they don't realize that it's right in front of there noses. I won't tell you anymore because I don't want to spoil it. Although I probably already have because I'm not very good at retelling what a story's about. So if it doesn't sound interesting I didn't do it any justice. I really think you should read it. Here's a picture.
The Black Tattoo Cover