Hsien-Ko is a character in Capcom's Darkstalkers fighting series, with her first appearance being Night Warriors: Darkstalkers' Revenge. She is based off of the Jiang Shi, a Chinese vampire or undead that hops around with its arms outstretched. She is a Dark Hunter, which is someone who hunts and kills Darkstalkers.
Her twin sister, Mei-Ling, and her were born in the 18th century, where their village was attacked by the dead. Their mother died in this attack and they used a prohibited technique to save her soul, which turned them both into Jiang Shi. This also gave them both mysterious powers, with Mei-Ling becoming the seal on Hsien-Ko's hat, which allows her to control her power.