fiction - How to prevent seeming like a Marty Stu-ish villain is cheating?

In a story I'm writing, there's a villain who is a genius strategist that can get anything he wants, whatever it is, by developing perfect strategies that can have only two possible outcomes: 1, success, or 2, success. His plans never fail because he always has a plan B, and each plan B has a plan B, always thinking of all possibilities and things that can ruin his plan and coming with a solution to each one of them. If that's not enough, he's also a powerful, almost invincible fighter, heir of two special abilities. Oh, and he also becomes immortal (though he can get killed in a specific, story way), and is an emperor.

In the end he is defeated by a flaw in his logic and a detail he didn't think about in one of his strategies (and by brute force too).

But sometimes you have the impression that he (the villain) is cheating, as he always figures out stuff and is always a step ahead and ends up winning, with no one able to defeat him in whatever way (except in the ending, along with specific story reasons), no matter what the heroes do, as if he is that invincible because the writer is "helping" him to achieve/win, and thus breaking the suspension of disbelief.

So how can I make it so that this quasi-invincibility or "Marty Stu-ness" is something to be amazed at, instead of something that breaks suspension of disbelief (besides justifying)?

Answer

There is nothing wrong with a hypercompetent antagonist.

The Mary Sue / Marty Stu is usually only perceived as bad writing when it is the protagonist. A story centered around a hypercompetent viewpoint character favored by faith is boring because the story offers no real challenge for such a character. But if you make the antagonist hypercompetent, you are doing the opposite. You provide the viewpoint character with an extraordinary challenge to overcome. You can create a lot of suspension based on how the viewpoint character will beat that overpowered villain. And if you can find a way to pull it off without using a deus ex machina or suddenly making the protagonist even more competent, you will likely end up with a pretty good climax to your story.

The only thing you need to watch out for is that the contrived plans of the villain are plausible. When you want to pull off a "Ha! Losing was part of my plan all along because [thing you wasn't aware of]", think about the following:

• Was it actually possible for the villain to plan this? Or does the plan hinge on some information or resource the villain couldn't possibly have access to? (Using some foreshadowing can help to bridge such plotholes)


• Is it believable that the antagonist could keep that plan B a secret?


• Does it actually make sense resource-wise to prepare both plan A and plan B? Wouldn't it have been more economical to invest slightly more resources into one of these plans to make sure it succeeds?


• Is plan B actually a plausible contingency for plan A? Or does the opportunity to switch to plan B only present itself because the villain was extremely lucky? For example, does plan B rely on precise timing of events the villain can not control or predict with sufficient accuracy? Or on certain people making certain decisions when they could just as well decide differently?


• If the villain planned for plan A to fail and plan B to succeed, was plan A actually required in the first place?