In the climax of Alan Moore and Dave Gibbons’ masterpiece Watchmen, Nite Owl II and Rorschach confronted Ozymandias. It was a scene we’ve seen before. Heroes figure out what is going on and confront the villain. Aware of their approach, Ozymandias doesn’t only prove equal to the task but he easily dispatches of them. With his former teammates lying prone he reveals his master plan. What makes this scene so iconic is that it flips a common comic book trope on its head. He goes through his entire plan, but he differs from most villains in comics in that it was too late for his plan to be stopped. Remove that difference and we’re still left with a man who had to share his plan with those who tried to stop him. Why is it that super villains find the need to share this? To get to the root of this we first have to understand the difference between heroes and villains. In a work such as Watchmen what separates good from evil is left up to your perspective. Ozymandias is willing to kill three million people to save more. Rorschach is deemed a hero despite being a full on bigot. It attempts to give a realistic representation of the shades of gray that exist in life. In comic books the lines between good and evil aren’t so vague. Superman is good. Spider-Man is good. Some such as Wolverine, Batman, and Punisher get dangerously close to the lines but are also ultimately good guys. They are heroes in the sense that they are doing what they do to protect others. They often find themselves whether willingly, or not so willingly, teamed up for the cause of saving the world. While there are rough patches they manage to work things out. Teams such as Justice League of America and the Avengers are formed of superheroes that, mostly, swallow their ego and bounce ideas off of each other to come up with the most effective way to overcome the challenge. This is not to suggest that super-villains. There are examples such as Spider-Man’s Sinister Six, Flash’s Rogues Gallery, the X-Men’s Brotherhood of Evil Mutants, and so on. What we consistently see is a clear-cut leader and his followers (Magneto with the classic Brotherhood of Evil Mutants), and lesser villains who join together to thwart a common foe (Sinister Six, Rogues). An example that proves how bad an idea it is for powerhouse villains to get together is displayed with the Secret Society of Super Villains. A fantasy dream team of villains put together to combat the Justice League always found itself strife with battles of ego between the likes of Darkseid, Lex Luthor, and Gorilla Grodd among others.
At the core a villain doesn’t want to share credit, and doesn’t want to feel threatened. Most of all when they succeed (for they never consider defeat) they don’t want to share any of the world that they now control. So they plan, and plan, and plan. Their minions (or followers if minions is too dismissive for your tastes) carry out their work and they are mostly isolated from the rest of the world.
A byproduct of not wanting to share credit of the spoils is the lack of equals that they respect to tell them how great the idea is. The yes men who surround super villains will deliver praise, but no matter how self-absorbed they are aware of the reason why this praise is delivered. So back to the initial question: why would a super villain share their plan with their rival before (or after) it is completed? In truth it is because whether or not they’d like to admit it the hero is the closest thing the villain has to an equal. To let them die, or for the plan to succeed, without the hero knowing everything that went into it would leave their accomplishment devoid of that acknowledgement.
Where the heroes have a process of multiple eyes, and ears to come up with the best plan to save the world, the villain only has him or herself. Despite Watchmen holding itself a part from the rest of the genre of superhero comics, it held true here. He shared his plan the same way Dr. Doom has on countless occasions in battles with the Fantastic Four. And the reasoning is simple: to feed their ego. Not only are they about to win, but also there’s nothing they could do. This is validation for all their planning. Proof that they can go about this all on their own.