Character Analysis
The Hunk
When we first meet Westley, he's nothing more than a handsome young farmhand who works for Buttercup and her parents. Buttercup totally takes him for granted and assumes that he's stupid because the only response he ever gives to anything she says is, "'As you wish'" (1.121). Little does she know that the reason he gives this response is because he's absolutely devoted to her—like, dude really means what he's saying. It's not until another woman (the Countess) starts hitting on him that Buttercup realizes Westley is a beautiful young man with a mind of his own.
Lying in bed, Buttercup can only fantasize about Westley and mourn the fact that she might lose him to another woman. She tries to convince herself that he's not all that hot, but doesn't succeed; after all:
The farm boy had eyes like the sea before a storm, but who cared about eyes? And he had pale blond hair, if you liked that sort of thing. And he was broad enough in the shoulders, but not all that much broader than the Count. (1.135)
You know who likes that sort of thing? Buttercup, that's who. So at the end of the day, she has no choice but to accept how handsome and awesome Westley is. Because he is awesome in addition to easy on the eyes—he sets off to seek his fortune before marrying Buttercup in order to provide better for her. It's just such a shame that the guy dies at sea before they can actually be together…
The Man in Black
The next time we see Westley, he has returned as the man in black. We don't know it's Westley yet because he's wearing a mask—and because William Goldman loves to throw surprises at us. All we really hear at first is that the man in black likes to hang out in high places and stare down at Buttercup as she walks through the town square of Florin. Goldman also makes the guy super intriguing by saying:
His mask was black, blacker than raven. But blackest of all were his flashing eyes. (5.22)
For all we know at this point, the man in black is going to be the villain of the story. He's rocking the outfit, that's for sure.
The more we learn about the man in black, though, the more impressed we're likely to be with all his skills and smarts. For starters, he wins a swordfight with Inigo Montoya, the dude who's supposed to be the greatest swordfighter in the entire world. Try as Inigo might to win:
[…] he was blocked. By the man in black. He was shackled. By the man in black. He was baffled, thwarted, muzzled. (5.602)
It's not until the man in black has safely captured Buttercup that he pulls off his mask and reveals himself to be Westley. Okay, okay—some of you might have seen that coming. But the fight scenes leading up to this revelation are still cool.
The Hero
Once Westley has returned to the story as his handsome, unmasked self, he's ready to take on the role of hero. And as a hero, the first thing he tells Buttercup is how much he loves her:
"Do I love you? My God, if your love were a grain of sand, mine would be a universe of beaches." (1.184)
Okay, yes, this is a pretty lame metaphor and Buttercup doesn't really understand it, but Westley's trying his best here and he's really tired, so cut the guy some slack.
Oh yeah, and there's one little problem: Moments after Westley reveals his true identity, he gets captured by Prince Humperdinck and tortured by Count Rugen. So much so, that the next time we see Westley, he's a totally broken man. As the author notes, "In humiliation, and suffering, and frustration, and anger, and anguish so great it was dizzying, Westley cried like a baby" (6.284). Yikes. It's pretty rough to see our hero in this kind of position, and things don't get much better when he actually dies at the hands of Humperdinck…
Yup, dies. You read that right. Luckily, a wizard named Miracle Max is able to bring him back to life. But for the rest of the book, Westley doesn't really have the strength to do any fighting. He can only come up with plans and hope that his friends Inigo and Fezzik are able to carry them out. So in a way, he's even more of a hero because he has to rely completely on his brains—and manages to come out on top anyway.
Whether a lowly farm boy ignored by the girl he loves or a barely-returned-from-the-dead hero forced to rely on his wits instead of his sword to survive and save, well, the girl he loves, when it comes to Buttercup, at least, nothing is going to stop Westley.
Westley's Timeline