Judging by the steady increase in popularity, in conjunction with the years, it seems as though it is a direct realtion the the character ANYA from tv's Buffy the Vampire Slayer. Personally, after Willow, she was my favorite female character on the show. It is a beautifully exotic sounding name. Her full name on the show was ANYANKA, ans she was a vengeance demon-turned-human.
Anya Seton (1904-1990) was an excellent author of historical novels during the period 1941-1975. All of her books were bestsellers. She was christened Ann but adopted Anya as her pen name.
Anya is a young woman residing in Harrogath (Act V, the special added-on act) in Diablo II: Lord of Destruction. She identifies items in Cain's place and will sell unidentified items. After beating the Act, she will personalize a weapon with the player's name.