Slayers
In every generation there is a Chosen One.  She alone will stand against the vampires, demons and the forces of darkness.  She is the Slayer.
There can be only one?
Well, this isn't Highlander, but since Season One of Buffy we were led to believe that there was and could only be one Slayer at a time. Fair enough. Then Buffy goes and dies and screws everything up. What a disaster that turned out to be.

Along came Kendra. Kendra was given to her Watcher at a young age by her parents, because they thought it was the right thing to do. Her fighting technique is flawless, but she has no real.... personality.  She has led the lonely life of a Slayer. No family, no friends, nothing but her destiny. So then Dru kills her. Oops. Another Slayer's dead. Guess what happens next?

Next comes Faith. Faith is fiesty and does pretty much whatever she wants. She doesn't care about silly things like consequences. She likes to party. And party. And party. She loves her "job" as the Slayer and gets a major rush out of it. Unlike Buffy who does it cause it's her destiny, or Kendra who did it because it was what she was trained to do and it is an honour. Faith does it for the fun of it.

So Faith turns evil. (Bet you didn't see that coming!!) And then there's a rogue Slayer running around killing people. Oops. So what do you do, huh? That's right! Kill each other of course. Buffy puts Faith in a coma, but guess what? After 8 long months, Faith wakes up. Oops.

Faith goes on the rampage, stealing Buffy's body (that was a surprise!) and then doing very naughty things (including Buffy's man.) She eventually (after giving Buffy her body back) ends up in LA to terrorise Angel and Co. After many painful (though mainly for Wesley) and heartwrenching moments, Faith does the good thing and turns herself in.

Meanwhile, back in SunnyD Buffy deals with being the only Slayer on duty. After all, she has what none of the previous Slayers had: the Scoobies. And right glad we are of that fact!!

What is the world coming to? How many Slayers can we have? Who knows. All I know is the world is a much safer place (matter of opinion!!) having a Slayer (or two) around.
Buffy and Kendra
(B) "Then why the hell did you attack me?"
(K) "I thought you were a vampire."
(B) "Ooh, a swing and a miss for the rookie."

(B) "C'mon don't make me do the chick fight thing."
(K) "Chick fight?"

"Get a load of the She-Giles."

"I'm Buffy, The vampire Slayer. And you are?"

"What are you going to do, B? Kill me- you become me. You and me girlfriend. We're enemies."

(B) "Faith. You don't get it. You killed a man."
(F) "No. You don't get it. I. Don't. Care."
"The great thing about being the Slayer? Kicking ass is comfort food."

"Faith's turned to the dark side of the force."

"Being a Slayer is not the same as being a killer."

"What'd you think? I'd wake up and we'd go for tea? You tried to gut me, blondie."

"It's an adventure, great, but for me it's destiny. It's something I can't escape, something I can't change. I'm stuck."

"God, I could eat a horse! Isn't it crazy? Slayin' always makes you just hungry and horny."
Faith