Character Analysis
We don't know it at first, but Count Rugen is actually the dude who killed Inigo Montoya's father. On top of that, the guy is an expert in the field of pain science. Yup, you read that right. He's an amateur torturer who one day hopes he will write a great book about pain; he says:
"At the present I'm engaged in writing a book. My book. The book, I hope. The definitive work on pain, at least as we know it now." (6.255)
To this end, he builds a machine that's designed to inflict the maximum amount of pain on whatever creature he hooks up to it. In this book, that unlucky creature just so happens to be Westley. When Rugen first introduces his machine to Westley, he boasts:
"This is the machine […] I've spent eleven years constructing it. As you can tell, I'm rather excited and proud." (6.249)
And by using this machine, he hopes to learn everything he needs to know about pain in order to become famous as a great scientist. In this sense, Rugen is more of a classic villain than his boss, Prince Humperdinck. While Humperdinck causes pain out of annoyance or insecurity, Rugen causes pain because it brings him great pleasure and satisfaction—it's something he's fascinated with, an end in its own right. He announces this to Westley when he says:
"If my experiments are valid, my name will last beyond my body. It's immortality I'm after, to be quite honest." (6.273)
Ah yes, immortality through torturing and killing others. Stay classy, Rugen. The funny thing about his quest for immortality, though, is the fact that he dies shortly after making this statement. Ha. The guy doesn't even realize that Inigo Montoya, the boy he orphaned more than a decade ago, has tracked him down and is going to kill him. But we know. Oh yes, we know.