The Devil's Right Hand: HandCannon: Origins

Duke LaRue is a Gulf War vet who lost his right arm, his right mind, part of his skull and more than a few of his marbles in a friendly fire incident. Now he's a lost soul hovering around the Texas/Mexico border pulling petty crimes, hooking up with tourists, and trying his best not to wake up in jail EVERY morning. But a chance encounter with the heiress to a cartel fortune and her would-be killers on a midnight beach turns out to be the first stumbling step towards his future as a cybernetic weaponized henchman-for-hire. Because even the bad guys have to start somewhere.