“Potential,” by Rebecca Rand Kirshner
Rona and Vi are out in a graveyard, looking scared and for good reason: something in here is hunting them.
Oh, wait, it’s Spike. He knocks Rona aside and takes a juicy bite out of Felicia Day...
...then it turns out, naturally enough, to be a training exercise. Buffy and the other Slayettes are on hand to debrief on why the two got killed. Rona whines about how it’s not a fair fight, since she and the others don’t have Buffy powers. (She could be whining about why she’s been ruled “dead” when all Spike did was give her a push, but that doesn’t occur to her.)
Buffy tells them all that that they have potential that ordinary girls lack—vampire-fighting instincts, basically— and talks a bit about learning to make the fight their own, even if what their finely tuned instincts are saying is “Run for the hills, wimp!” She and Spike get into a little demonstrative sparring, which turns into a tender gravestone-side moment where she’s worried she’s hurt him. And all but petting his manly bruises.