I’ve talked a good amount about messing with the minds of your opponents. But there’s one thing I’ve found that tends to be really good for the job with minimum effort—no monetary outlay, no risks of experiments going horribly wrong, just a little thought and a little bit of talking.
Compliment them. You’ll love the looks on their faces.
See, giving protagonists compliments throws off the dynamic between you and them. When the compliment’s sincere, it makes you seem more reasonable, or at least more polite; bear in mind that the urbane, clever villains often are the ones that last, and it’s not just because they generally have the sense to avoid revealing themselves too early. Complimenting the protagonists might imply to them that you’re looking for a good career-antagonist-type relationship. For the ones that took up their story-worthy deeds because they wanted to be Special, it might touch off that little bit of warm-fuzzy—this can serve as a diversion, a way to get them to spare you should you lose, or possibly a way to just play off of their hidden issues with authority figures. A sincere compliment with a caveat can show that you recognize their skill, but you’re not really intimidated by it. Compliments with a little extra bite, or praising them for things they aren’t proud of (like what a titanic mess they made of that last battle site, or how well they followed your plan for them) can provide an excellent goad. And there’s always choosing a good double meaning and creeping them out!
Just because using a compliment can be tactically helpful doesn’t mean you have to be sincere. Snark is reasonable. Back-handed compliments, or compliments that elevate one member of the group over the others are fair game. (And if you’re in it for the long run, you can start with the zinging compliments and then let the ones who’ve “proven themselves” to you get the compliments at the expense of their allies or even a few sincere words. They might not even realize what you’re doing.)
Neither does it mean that complimenting and killing the opponent are mutually exclusive. You can praise him now and bury him later—and later can be “half a minute later” if there’s tactical advantage and it’s feasible. I don’t find it quite as much fun, but it’s boring if evil is a truly monolithic entity, don’t you think?
Everything can be a weapon. Praise is no exception. So consider saying something nice—it might be a lot better than saying nothing at all.