It's been a bit since I've read this novel and I was trying to find it recently so any help would be much appreciated.
From what I remember of the novel the book starts with a group of mercenaries (or possibly soldiers) who need to stop a bomb from going off. Something having to do with the bombs unleash nightmare like things (or at least things coming out of nightmares and people's imaginations. And it creates other people, who aren't people). Prominent things that happen throughout the novel includes backstory on the main character who had all sorts of military training (like stunt driving).
There are flashbacks from when he is a child playing with his friend in the sandbox at the park, and he talks about how his friend and his friend's parents practically raised him. His best friend's older brother ends up dying.
The twist at the end of the book is kind of big and helpful, the not spoiler has to do with the main character's name.
The main character is actually created from whatever weapon happens in the beginning of the book, at the beginning of the novel he is kicked out of his best friend's truck but survives because he is new. He realizes because he goes to his best friend's parents and they tell him he looks just like his best friend's older brother.