I've been thinking about a cool concept about an immortal hired gun working for the devil, where he gets assigned horrible tasks to fulfill based on their clients. These clients happen to be highly depraved, societally outcast, or plain old evil. Some of the topics I'd like to cover involve cannibalism, feederism, the classic "pedo", human trafficking+mindbreak, child soldiers etc.

The catch is the guy is more or less unemotional and doesn't particularly react or care about things he does(in fact an interesting choice is to have him be mute). The more interesting thing is how he goes to achieve the tasks the clients request of him, and how society reacts to his actions, along with the direct conflict between individual clients and whatever authority is dispatched to handle the issue. In a way, the clients and the police/SJWs/whatevers that oppose them are the ones where you build a backstory and character arc.



You can have the guy work for clients with highly erotic tastes, painting a degenerate scene where they do whatever, and talk about how they want the guy to help them do something illegal or something. If I wrote it I would add additional scenea of violence and brutality, but that might be what you want. One interesting thing is to choose whether the guy suceeds or fails in his tasks, and how that changes the client's further motivations and actions, along with how others react. Also you can draft up new characters each chapter, focusing on them as "contracts" with different clients across the country.

Does this interest you OP?