The reason you are getting jokey replies is the way you asked the question, as it frankly sounds like you are joking.
That and truly devious people have no reason to help you (except to try to trick you), and the non-devious people don’t want to encourage more manipulative people. I am the latter.
I give up.
You could read some of the articles on gangsters over at Crime Library. Most of it isn’t as, well, Machiavellian as some of the suggestions in this thread, but it’s still worth a shot. For example Whitey Bulger is a guy that was a heavy in Boston’s underworld for decades while manipulating both the FBI and his fellow gangsters. He’s been on the FBI’s Ten Most Wanted Fugitives list for over a decade and is probably at this very moment sipping a cappuccino in Europe somewhere.
Get into politics.
Or read some book like “Dirty Tricks” by George Heyduke.
You think deviousness makes the world go around. It doesn’t, any more than trust, greed, seduction, or any number of abstractions. You described a snipers tactic earlier and complained when someone pointed out it wasn’t devious, and you asked people who disagreed with you not to reply; thus potentially cutting yourself off from information that could be useful, if only because sometimes you learn best what you personally believe by observing that which you disagree with in others. You couldn’t be bothered restating the question due to an emotional response, annoyance, and truly devious people hide genuine emotional responses and show only staged emotional responses. It also leaves the impression that you do not share the same definition of ‘devious’, and instead have imbued it with meaning that isn’t there. If you want to be deliberately misleading then you may have reached your goal. Assuming you want to rise to the level of ‘Evil Genius’ then you first have to try to become a genius, which involves a lot more study than just watching films and reading prose from wannabes like Machiavelli.
Research psychopathy, those people naturally intermix truth and lies, and they often rise to great power. Read up on magicians and con-artists, how they make people think something has happened when it hasn’t.
Most importantly learn from people you consider the opposite of devious, saintly folk or schmucks, learn why they don’t feel the need to be devious.