I guess the thing that caught my attention as a reader/writer, just from the commercials, was the idea that this guy is an assassin who is created by something approximating the Catholic Church. They might never say it explicitly, but that's what it looks like. According to the handful of reviews I've read this is kind of glossed over in the movie, but I think it's the most interesting thing.
So the writer in me started brainstorming in general. Why would a church take part in creating assassins? Is it just one church or several, each with their own group? It's kind of a paradox because, for me at least, when you think of church you think of modern-day churches in the United States that are very much about peace, love and forgiveness. But God only knows we live in a world where for some people, being a true believer (in whatever warped sense) means that you pick up a gun or a explosive vest and go out to kill people. And Christianity itself certainly has a storied history of trying to convert people by force. Still, that's the kind of thing that takes armies, not lone hitmen.
In the back of my mind my muse is weaving a thin plot about churches in the future where the folks in charge raise/hire/train people as bodyguards who are 'licensed to kill' by God in order to protect that church's high muckymucks, because... I don't know. Organized religion is outlawed? Different sects of some religion, be it Christianity-based or not, are in some gang-war-type war with each other? The Rapture has already happened and the world is in a panic but the church officials don't want everyone to know that it was the Rapture because then people are going to be, like, hey, why weren't you taken? But for all I know that happened in the Left Behind books. Urgh. It would probably help if I had any experience with organized religion in the last fifteen years...
Don't mind me. Just babble.