I'm almost late with this one - had unexpected company this evening.
In my Whedon-verse alphabet pattern, F is for Faith Lehane!
Sorry for the dark, fuzzy picture - it's almost midnight!
Faith is a Slayer - she's the Slayer who was 'activated' after Kendra, another Slayer, died - there's only supposed to be one Slayer, with a new one becoming 'active' when the last one dies. Kendra became the Slayer when Buffy temporarily died - I think Xander gave her CPR and she came back to life - so there were two Slayers. When Drusilla (a vampire) killed Kendra, Faith became the Slayer in her place.
Faith was played by Eliza Dushku:
Here's a LINK to read more about Faith; she was called The Dark Slayer because she had some serious issues! I didn't like her character, but she was very interesting! She treated Xander very badly, and Xander is like my third favorite character (Spike is my favorite) so I got to have a bit of a grudge against a fictional character, which is always fun :D
The knife goes quite well with Faith; it was given to her by the bad-guy Mayor of Sunnydale when she was helping him. Buffy later stabbed her with it and used it to lure the bad guy into a trap. It seemed quite effective in the show, but I wondered if it would be more than just awkward in real life? I can't see it being useful when you need to slice up a watermelon...
I think I need to go to bed XP