Anyanka.

Anya Christina Emmanuela Jenkins.
Ever the Wordsmith.
Anya was originally born in Sjornjost in Sweden around 855 with the name Aud. Married to a large man named Olaf, she spent her days caring for their home and their ever expanding litter of bunnies. Merely tolerated by the rest of the villagers, she was often told to take her furs and her literal interpretations to the other side of the river. Olaf sometimes spent his time at the local bar where a woman named Ranvieg was the barmaid. Aud was jealous and her husband tried to assure her of his feelings for her. Despite all of this, Olaf did commit adultery and Aud exacted her revenge by turning him into a troll. Impressed by her work, she was visited by a demon named D'Hoffryn. He referred to her by the name of Anyanka, much to her confusion, and revealed himself to be a patriarch of a family of vengeance demons. He offered her a job. He offered to make her a demon. For the next thousand years, Anyanka becomes one of the most infamous vengeance demons, specializing in justice for wronged women. She is a model for all other vengeance demons, and was partly responsible for causing the Russian Revolution in 1905.
In 1998, Anyanka traveled to Sunnydale, California to help Cordelia Chase. She befriended Cordelia, whose boyfriend Xander Harris recently cheated on her. She tried to get Cordelia to make a wish. Eventually, Cordelia wished that Buffy Summers had never come to Sunnydale. In that new reality, the vampires had taken over Sunnydale and when Giles found Anyanka's amulet around Cordelia's neck, he began to research. He summoned her and managed to destroy her amulet, which was her power center. The world reverted back to normal and Anyanka was left a mortal. Remaining as a student at Sunnydale High School, Anya attempted to get her power center back. She eventually failed and tried to adjust to life as a human. She attended the prom with Xander Harris and was trying to make another date with him when she learned of the Mayor's ascension. She tried to talk Xander into leaving with her, having witnessed an ascension centuries before. When he refused, she left Sunnydale.
She returned to Sunnydale, wanting to see Xander again. In attempt to get over her feelings for him, she suggested they have sex. Afterwards, Xander thought that their relationship was over, but Anya had other plans. She continued to see him and the two eventually began dating. Anya didn't exactly fit in with Xander and his friends. Nonetheless, she kept trying and eventually told Xander that she was in love with him. In this time, Anya began helping with research and sometimes helped with the knowledge she had acquired throughout her long life.
Anya became a more permanent member of the group. When Giles purchased the magic shop, Anya began working for him. Xander helped her with her people skills when dealing with customers, though she preferred working with the money. She took an active interest in all aspects of the business and began saving the money she made and investing it. Her relationship with Xander also deepened. Despite some problems, he eventually told her that he loved her. Anya showed some nervousness when the Watchers Council visited, fearing they would learn of her ex-demon status. Facing an apocalypse, Xander proposed. Believing that Xander was only asking her to marry him because he believed the world would end, she said no. She said yes, however, when he explained that he was asking because he felt the world would be saved and they would have their entire lives ahead of them.
After Buffy's death, Xander delayed telling his friends about their engagement. Anya took over full management of the magic shop when Giles returned to England. He remained a silent partner. Upon bringing Buffy back from the dead, Anya tried to get Xander to tell everyone about their engagement. When Giles returned to see Buffy, Anya was happy to see him but quick to remind him that she was running the store. Xander eventually told everyone about his engagement to Anya on Halloween. An impromptu engagement party was thrown where Xander began to express some doubts. He expressed some doubts yet again, this time through song, after he summoned a demon so he could find out if they'd get a happy ending. Anya and Xander began feeling stressed over planning their wedding. Anya intended to invite several of her demon friends, including D'Hoffryn and fellow vengeance demon Halfrek. The wedding day arrived with Anya overjoyed. Her happiness was shattered, though, when Xander disappeared. He was spoken to by an old man who turned out to be a demon that Anya had cursed. When Xander returned, he explained that he'd been having doubts before and could not go through with their wedding. D'Hoffryn visited Anya, offering to give her back her old job. She accepted and tried to get Xander's friends to help her curse him. When that failed, she tried to get Spike to curse him. Instead, the two got drunk and had sex. The act was seen by Xander, who immediately attacked Spike. Anya later explained to Xander that sleeping with Spike was solace. When Tara was killed and Willow went beyond simple vengeance, Anya helped with trying to save Willow.
After the battle with Willow, the magic shop was destroyed. Anya made her living by being a vengeance demon, but didn't find it as fulfilling as she previously had. The other vengeance demons believed that Anya had returned to them after she slaughter an entire fraternity house. Feeling guilty, she asked D'Hoffryn to take it back. He explained to her that in order for that to be done, the life of a vengeance demon would have to be taken. Anya agreed and Xander tried to stop her. D'Hoffryn summoned Halfrek and killed her, explaining to Anya that you never go for the kill when you can go for the pain. Anya's days as a demon were over and she began to put her life back together, becoming a more a part of the group again. She once again helped with research and the knowledge she'd gained over the years. As the final battle with the First Evil approached, Anya and Xander found themselves getting closer again. Anya decided that in the final battle, she would fight just as humans did. It was mortal and stupid, but kind of beautiful. In the end, in the battle at the high school, Anya was killed by a Bringer. Xander looked for her as the school collapsed and when Andrew told him that she died protecting him, Xander said it was just like Anya to always do the stupid thing.
|Anya <3 Xander|
"You're a good person and a good boyfriend and... and I'm in love with you."