This is a cross between Buffy and "Lord of Light" a sci-fi book written by Roger Zelazny. I do not own the rights to either of these things, so don't sue me.
Quietly does it, thought Buffy as she crept towards Giles' archives, you don't want Giles to find out you're stealing from him in order impress your vampire boyfriend.
So focused was Buffy on not making any sound that she nearly jumped out of her skin when Giles suddenly called out "Buffy!" from right beside her.
As it was, Buffy jumped a foot in the air and said "Nothing! Hi!" in a way that would've made even Willow suspicious. Speaking of Willow - if Buffy was going to see those Watcher diaries, then Willow was going to have to steal them. Buffy beckoned to her friend when Giles back was turned.
"Yes, I meant to talk to you about tommorow. I had planned to teach you some battle techniques, as vampires tend not to hunt on Halloween, but that little Principal man insists that I take a group of children Trick-or-Treating." Giles said mournfully, as he stacked books.
Buffy, in order to draw attention away from Willow who was even now creeping towards Giles' collection of Watcher diaries, sat on the table next to Giles and said "Hey, that's a good thing! You know, so you can get out of the library, have some fun..." she trailed off in the face of Giles' distinctly unamused expression.
"I do not consider shepherding sugar-crazed children from house to house whilst dressed in a costume to be fun." Giles said primly.
"Hey, who knows, you might enjoy it! Besides, if you get a good enough costume, you might impress Ms. Calendar." Buffy said, trying to draw Giles' gaze back to her and away from Willow who was currently sneaking out with the requisite book.
"Yes, well, I still don't think that it's a good idea." Giles murmured.
"Nonsense. Xander, Willow and I are going down to this new costume shop after school today, and you are going to come with us. Even if I have to drag you, Giles, and you know I can." Buffy declared, then said "Anyway, I have to go, see you later." and rushed out, leaving a bemused Giles behind.
Ethan was rather more than colossally surprised when Ripper, of all people, walked into his store, with three teenagers (he wondered which was the Slayer) in his trail.
Naturally, Ethan couldn't go out there wearing his own face - Giles would recognize him in a heartbeat, and then he'd never get his plan going. Fortunately, Ethan specialized in transformation magic, and it was a simple matter to cast a quick glamour spell on himself. It wouldn't pass muster if Giles actually looked too hard - glamours tended not to work too well on other magic-users - but Ethan doubted that Giles would be that observant. He never had been before.
So Ethan walked up to the quartet, taking care to change his walk and his voice so that Giles wouldn't recognize them, and asked grandly "Have you seen anything that tickles your fancy?"
Xander and Willow held out a toy gun and a ghost costume respectively, whilst Buffy was still searching the shop. Giles, feeling uncomfortable, muttered "I was rather hoping that I might go as a librarian. Or, better yet, not go at all."
"Aw, c'mon Giles, pick a - ooh!" said Buffy, cutting herself off when she suddenly saw the lovely, fairy tale princess dress that would be sure to set Angel's pulse racing (or it would, if he even had a pulse).
"Yes, well, I'm not entirely sure that a dress is my style." Giles said dryly.
"Oh, but I can't afford this." said Buffy sadly, fingering the dress.
"Don't let a little thing like money stop you! I feel quite moved to make you an offer you can't refuse." Ethan said, stepping forward.
"Really?" Buffy asked, eyes aglow with hope.
"But of course. Assuming, that is, if you help me choose a costume for your obstinate friend." Ethan said.
In quick succession, Giles rejected a doctor's scrubs, a James Bond-style tuxedo, an array of interesting masks, several vampire and demon costumes, and something that looked like a robot. If Ethan hadn't been determined to make Giles wear something, he would have certainly moved on to easier pickings.
Oddly enough, it was the Buddha costume that finally appealed to Giles. "You're always going saying that I should relax, Buffy, and one doesn't get much more relaxed than someone who's enlightened." he said.
Ethan tried hard to suppress his mirth at the idea of the Buddha walking around Sunnydale whilst demons and vampires roamed the town, but couldn't quite manage it. Luckily, he hid his laughter behind a cough, and quickly sold it to Giles before he could change his mind and walk out of the shop empty handed.
Later that night, when Ethan began the incantation that would invoke Janus, he had considerable difficulty focusing on what he was doing. His mind kept harking back to the idea of Giles in that Buddha costume, trying to preach to the mindless demons his spell would create.