Hsien-Ko (Lei-Lei in Japan) is a video game character from Capcom's fighting game series Darkstalkers (Vampire in Japan). She appears in Marvel vs. Capcom 3 alongside Morrigan and Felicia. She is a Jiāng Shī, a type of zombie from Chinese folklore.
Hsien-Ko (pronounced Shen ko) was born around the 1730s with a twin named Mei-Ling (Lin-Lin in Japan). During this time, ghosts and spirits of the dead arose from their resting places and attacked a rural Chinese village.
After their mother was killed by a powerful demon (said to be Pyron), she and her sister decided to use Tensei-no-Jutsu to save her, but they used a prohibited sub-division of this technique, Igyo Tenshin-no-Jutsu, and fought to release their mother's soul from the dark. This turned the twins into a jiāngshī (僵屍 "stiff corpse"), a type of Chinese vampire. This, however, also gave the two unusual abilities which the two use to fight for their purposes. Mei-Ling is actually the ward-paper (fú) on Hsien-ko's hat.
Hsien-ko's powers cannot be fully controlled unless Mei-Ling does so herself when she becomes the ward-paper. If she separates from Hsien-ko, many of Hsien-Ko's abilities no longer work (other times it is said that she loses control of herself), so they essentially fight as one. Hsien-Ko is the "body", and Mei-Ling the "mind". Once in a while, Mei-Ling does come out to team up with Hsien-Ko (as seen by their Dark Force ability in Darkstalkers 3). In the anime, Hsien-Ko seems to be more in control of her body, as she is warned by her sister not to kill their assailants when they are attacked by a group of drunken humans. The two fight many battles during Night Warriors, and eventually win the freedom of their mother's soul, but at the cost of their own lives. Yet, before their death, the spirit of their mother claims she will not let oblivion become their reward, and the twins' souls are reborn as infants in a new life.
In Vampire Savior, the reincarnated sisters live a happy, normal life. However, on their sixteenth birthday, weird things begin to happen to them. They have the same dreams, and the next night, they fall into a coma, and their souls were transported to the Dark Realm, which called to them. They found themselves in weird costumes, and although their memories of their past life are sketchy, things begin to slowly come back to them. They regained their unique power of transformation they had lost during the death of the life preceding this one. Now as saviors and hunters once more, they must find their way home to Earth Realm.
After the events of Vampire Savior, the sisters are engulfed by darkness, but their mother's spirit saves them, and they return back home as humans once more.