What follows this is the kind of post you'll probably seeing a lot more of. Me working through ideas by writing them down. The trick is not to show my whole hand lest the idea get stolen, spoiled, or a combination of both.
It makes enough sense, but it also introduces a whole new problem.
Being a killer that...talented (for lack of a better euphemism), why would he be limited to just the criminal underworld? Why would he not gain the attention of intelligence agencies?
Wait - that's it. Agencies. Plural. The concern was that introducing government and potentially taking the story global would have shifted the narrative away from the original structure.
But, if it's more than one country...that may no longer be a concern.