Buffy The Vampire Slayer S4 Ep 16 - F2F Body Swaps

Season 4 Episode 16 Who Are You?
Faith challenges the vampires inside, and she quickly dusts the other vamps before taking on Boone. As he starts talking about how Adam has shown him the way forward, Buffy stakes him from behind. The two Slayers fight and Faith gets Buffy on the floor and starts to furiously punch her (own actual) face while calling her "nothing," "disgusting," and a "murderous bitch." Buffy grabs Faith's hand with the Katra, and the two switch back to their own bodies. Faith runs away, leaving Buffy stunned.