Ah yes. My "favorite" part...but only after this build up:
Get It Done - Buffy Episode 7x15 Transcript
BUFFY
The First isn't impressed. It already knows us. It knows what we can do, and it's laughing. You want to surprise the enemy? Surprise yourselves. Force yourself to do what can't be done, or else we are not an army—we're just a bunch of girls waiting to be picked off and buried. (Spike stands and walks toward the door) Where are you going?
SPIKE
Out. Since I'm neither a girl, nor waiting. All this speechifying doesn't really apply to me, does it? (walks away)
BUFFY
(calls after him) Fine. Take a cell phone. That way, if I need someone to get weepy or whaled on, I can call you.
SPIKE
(turns to Buffy) If you've got something to say—
BUFFY
Just said it. You keep holding back, you might as well walk out that door.
SPIKE
Holding back? You're blind. I've been here, right in it—fighting, scrapping...
BUFFY
Since you got your soul back?
SPIKE
Well, as a matter of fact, I haven't quite been relishing the kill the way I used to.
BUFFY
You were a better fighter then.
SPIKE
I did this for you. The soul, the changes—it's what you wanted.
BUFFY
What I want is the Spike that's dangerous. The Spike that tried to kill me when we met.
SPIKE
(angrily) Oh, you don't know how close you are to bringing him out.
BUFFY
I'm nowhere near him. Dawn, get the potentials upstairs, and break out that emergency kit.
LATER:
RED HAT SHADOW MAN
SUBTITLE: Herein lies your truest strength.
BLACK HAT SHADOW MAN
SUBTITLE: The energy of the demon. Its spirit.
BROWN HAT SHADOW MAN
SUBTITLE: Its heart.
BUFFY
This is how you—
RED HAT SHADOW MAN
SUBTITLE: Created the slayer? (nods) Yes.
Black smoke comes out of the box in long tentacles; it seems sentient as it dances around the circle. The men keep tapping their staves rhythmically.
BROWN HAT SHADOW MAN
SUBTITLE: It must become one with you.
BUFFY
No! (struggles against her chains)
RED HAT SHADOW MAN
SUBTITLE: This will make you ready for the fight.
BUFFY
By making me less human?
RED HAT SHADOW MAN
SUBTITLE: This is how it was then. How it must be now.
BLACK HAT SHADOW MAN
SUBTITLE: This is all there is.
Buffy struggles against her restraints in vain as the black smoke comes toward her, entering her body through her nose and ears.
Fade to black.
ACT IV:
37 EXT. CAVE IN DESERT - DAY
Resume. Buffy's screaming as the black smoke tries to enter her body. The men just stand there, watching. The smoke can't get in through her head while she's screaming, so it rises to the ceiling of the cave and comes back down to her, encircling her hips. Still, she resists.
BUFFY
(through gritted teeth) Make this stop!
RED HAT SHADOW MAN
SUBTITLE: This is what you came for.
Typical "Do as I say, not as I do" Buffy of season 7. She even goes so far as to provoke Spike to embrace his darkness, but she won't hers, not for the strength she demands others force themselves to take. She's above all that, in her mind.
At the very least the writers could have Anya (and others) call Buffy out on it (not just this, Buffy was this way a lot in this season) rather than the trivial stuff they came up with. I wonder, did the writers really miss it, or did they just hope the audience would?