I'm with you regarding superheroes/villains rape, Jab. If they do tell that story, it should be with a character they have no intention of using again, because realistically, his life expectancy after would be measured in weeks. One thing I liked about the book 'Empowered' when I checked it out was this notion of 'The Unwritten Rules' that supers society goes by to explain why even in a world filled with such super jerkasses, the title character that was potentially such rape bait never got so much as molested. There were just certain things you didn't do, and raping a helpless foe was one of them.
If I ever did my own setting, it'd be something largely like that. Most villains would actively avoid trying to learn a superhero's secret ID, because heroes are intensely protective of said ID and their families, and going after a hero's significant other is just asking for large amount of pain and/or a grizzly end. Likewise, rape of a hero OR villain is dealt with quickly and with extreme prejudice. You figure most villains are in the business to make money, a smaller percentage have a specific agenda, a smaller percentage still to rule the world, and a tiny percentage are basically super serial killers. The last group would always be small given the tendency of said characters to wind up dead (which is why I don't like such characters to be regulars in comics), and every other group would be composed of people that would have issues with folks who sink that low.
As for the Purple Man, I liked his portrayal in Avengers:EMH, where he was portrayed as someone who enjoyed flaunting his control over others, making him vile without the reprehensible rape stuff thrown in. To my knowledge, while he had done the stuff with Persuasion, he didn't become this serial rapist until Bendis got his hands onto him. If anything, I think the Persuasion bit was suppose to show why he didn't use his powers on women that way, rather than to be a justification for him being that way.