Carradine together with the stunning Perla Haney-Jardine as B.B. does not just break Kiddo's heart but deeply touches the viewer with striking eloquence and intelligence on Tarantino's part.
Besides a thousand other examples, there's one which illustrates Bill pulpy and campy but never-the-less sophisticated view of the world and of course once more Tarantino's genius: A scene where Bill shot Kiddo in the leg to tranquilize her and while he's waiting for the injection to kick in, he's explaining in a brilliantly tarantinoesque metaphor what he thought of her escape from the Deadly Viper Assassination Squad.
Bill: As you know, l'm quite keen on comic books. Especially the ones about superheroes. I find the whole mythology surrounding superheroes fascinating. Take my favorite superhero, Superman. Not a great comic book. Not particularly well-drawn. But the mythology... The mythology is not only great, it's unique.
The Bride: [who still has a needle in her leg] How long does this shit take to go into effect?
Bill: About two minutes, just long enough for me to finish my point. Now, a staple of the superhero mythology is, there's the superhero and there's the alter ego. Batman is actually Bruce Wayne, Spider-Man is actually Peter Parker. When that character wakes up in the morning, he's Peter Parker. He has to put on a costume to become Spider-Man. And it is in that characteristic Superman stands alone. Superman didn't become Superman. Superman was born Superman. When Superman wakes up in the morning, he's Superman. His alter ego is Clark Kent. His outfit with the big red "S", that's the blanket he was wrapped in as a baby when the Kents found him. Those are his clothes. What Kent wears - the glasses, the business suit - that's the costume. That's the costume Superman wears to blend in with us. Clark Kent is how Superman views us. And what are the characteristics of Clark Kent. He's weak... he's unsure of himself... he's a coward. Clark Kent is Superman's critique on the whole human race. Sorta like Beatrix Kiddo and Mrs. Tommy Plimpton.
The Bride: Aso. The point emerges.
Bill: You would've worn the costume of Arlene Plimpton. But you were born Beatrix Kiddo. And every morning when you woke up, you'd still be Beatrix Kiddo. Oh, you can take the needle out.
The Bride: [does so] Are you calling me a superhero?
Bill: I'm calling you a killer. A natural born killer. You always have been, and you always will be. Moving to El Paso, working in a used record store, goin' to the movies with Tommy, clipping coupons. That's you, trying to disguise yourself as a worker bee That's you tryin' to blend in with the hive. But you're not a worker bee. You're a renegade killer bee. And no matter how much beer you drank or barbecue you ate or how fat your ass got, nothing in the world would ever change that.
The director gives his character Bill all the time he needs to finish his monologue, he's not rushing him to advance the story, he seems to be full of empathy and understanding for Bill to give hs character the freedom he needs to unfold. In an interview with Graham Fuller in 1993 he states: “When I start writing I let the characters take over. If you read my scripts, you'll see that the dialogue scenes just go on and on and on.” And although Kill Bill was not even on Tarantino's mind back then he definitely kept up his characteristic way of writing till present day and even got better.
Especially for David Carradine he wrote one of the most elegant roles of his career so far. Initially there was also Warren Beatty in competition for the role of Bill but luckily it ended up the way it did.
Bill is finally killed by the five-point-palm-exploding-heart technique Pai Mei told to Kiddo and the movie ends with her and B.B. taking off towards a new life.