anya

"For thousands of years I wielded the power of the wish. I brought ruin upon the heads of unfaithful men.
I offered destruction and chaos for the pleasure of the lower beings. I was feared and worshipped across the
mortal globe and now I'm stuck at Sunnydale High! A Mortal! A child! And I'm flunking math."

Character Profile
Character name: (human names) Anya Emerson , (Demon name): Anyanka

First appearance: The Wish (Season 3)
Traits/powers: As a demon: ability to alter reality for scorned females.
                      As a human: lacks tact, tends to say the wrong thing.
Anya becomes a regular guest star during and after the 5th series of "Buffy The Vampire Slayer".

For centuries, Anyanka was the patron demon for scorned women, they worshipped her, and she did devilish things to men who did these women wrong.
She first appears in Sunnydale to help aid Cordelia in her grudge against Xander, using her powers to transform Sunnydale into a place as though Buffy didn't exist.
To reverse the magic, Giles destroys Anyanka's power source (her necklace) and strands her on the mortal plane powerless.
Despite her protests, Anya remains on Earth.

Granting Cordelia's wish for vengeance that Buffy would have never come to Sunnydale, she turned the town into a destructive version ruled by vampires.
The spell was later broken along with her source of power, Anya's necklace. As a result, Anya was rendered powerless, and a mere mortal. Twelve hundred years old, and stuck in the body of a high school student. She attempted to get her powers back in the episode "Doppelgangland" by doing a spell with Willow that would bring her necklace back, but instead brought the vampire Willow from the alternative Sunnydale to the present.
Anya: "I'm eleven hundred and twenty years old! Just give me a friggin' BEER!"
Waiter: "I.D"
Anya: "Give me a Coke" (Doppelgangland)

She remained a mortal, and was forced to live the life of a teenager. Out of desperation for a date, Xander agreed to take her to the Prom. Then, Xander told her about the upcoming Ascension, and she was able to provide the Scooby Gang with some valuable information, considering in her many years of life, she'd witnessed an Ascension. Not wanting to stick around and see if she could survive a second, she ran away from Sunnydale but later returned, wanting to know where her relationship with Xander was going. Her approach to getting Xander was simple and direct, dropping her clothes to the floor and suggesting sex to an 18-year-old boy.

Making her occasional, but regular appearances helping out the Scooby Gang, Anya slowly learns the ropes of being a real human, while benefiting from her history as a demon.
She becomes a member of the Scooby gang and becomes the love interest of Xander, who teaches her the ways of humanity.

During a very emotional scene in the episode 'The Body' (when Buffy's mum dies) we get a great insight into Anya's character We see how she can't help but act inappropriately, how she feels confused about what to do and how to feel because she doesn't understand the concept of death:

ANYA: (crying) "I don't understand how this all happens. How we go through this. I mean, I knew her, and then she's, (sniffling) there's just a body, and I don't understand why she just can't get back in it and not be dead anymore. It's stupid. It's mortal and stupid. (still teary) And, and Xander's crying and not talking, and, and I was having fruit punch, and I thought, well, Joyce will never have any more fruit punch ever, and she'll never have eggs, or yawn or brush her hair, not ever, and no one will explain to me why. "

Season 6:
Anya and Xander get engaged. Xander leaves Anya at the alter, resulting in her going back to her old ways and becoming a Vengeance Demon.

Season 7:
We learn more about Anya's past.
Anya isn't quite the Vengeance Demon she once was. Having now experienced life as a human, she struggles to inflict pain on others (to the disappointment of DeHofren, her Boss).
Regretting something that she does, she tries to take it back, and losses her demon powers.

Real Life Info
Real Name: Emma Caulfield

Television Appearances:
Nash Bridges - guest appearance (1998)
Silk Stalkings - guest appearance as "Kate Donner" (1997)
General Hospital -series regular as "Lorraine Miller" (1996-1997)
Beverly Hills, 90210 - series regular as "Susan Keats" (1995-1996)
Weird Science - guest appearance as "Phoebe Hale" (1995)
Silk Stalkings - guest appearance as "Ray Washburn" (1995)
Renegade - guest appearance as "Cindy" (1994)
Saved by the Bell: The New Class - guest appearance as "Nurse Penny Brady" (1993)

Anya Quotes

"There's a hurry, Xander. I'm dying. I may have as few as fifty years left."
(The Replacement)

"You can't make it any different. I'm going to get old. And... you can't promise you'll be with me when I'm... wrinkly and my teeth are artificial and stuck into my wrinkly mouth with an adhesive."
(The Replacement)

"I'm just so excited. They come in, I help them... they give us money in exchange for goods... you give me money for working for you... I have a place in the world now. I'm part of the system. I'm a working gal."
(Family)

"Hmm. Humans make the same mistakes over and over. I saw it when I was a vengeance demon. Some guy dumps a girl, she calls me, I exact vengeance, blah blah blah, the next year, same girl, different guy. I mean, after you smite a few of 'em you start going 'my goodness, young lady... maybe you're doing something wrong here too.'"
(Triangle)

Anya: "I like you. You're funny, and you're nicely shaped. And frankly, it's ludicrous to have these interlocking bodies and not... interlock. Please remove your clothing now."
Xander: "And the amazing thing... still more romantic than Faith."
(The Harsh Light of Day)