Shao Hsien-Ko and her twin sister Mei-Ling trained in mystical arts within their Senjutsushi village. On their sixteenth birthday ceremony, Darkstalkers attacked, killing their master and their mother. Their mother sacrificed herself to protect them, trapping her own soul in darkness. To rescue her, Hsien-Ko performed the forbidden Igyo Tenshin technique, transforming herself into a Jiang Shi, a Chinese hopping vampire. Mei-Ling simultaneously became a paper talisman affixed to Hsien-Ko's hat, acting as a ward against Hsien-Ko's amplified, darker instincts. Bound together by this transformation, they became Darkhunters dedicated to fighting supernatural threats and hunting the Darkstalkers responsible for their tragedy.

After freeing their mother's soul, the sisters received reincarnation as a reward, living normal human lives until their next sixteenth birthday. That night, their dormant powers reawakened, drawing the attention of the demon Jedah Dohma. Jedah summoned their souls into his realm, Majigen, leaving their soulless bodies behind. Within Majigen, their mother's lingering spiritual intervention caused them to manifest in their previous Jiang Shi and talisman forms. Navigating the hostile realm with fragmented memories, they fought instinctively to survive and return home. Following these events, their souls reunited with their human bodies, leaving Majigen as a blurred nightmare. They resumed life as ordinary teenagers, retaining their reawakened powers and fragmented memories.

Hsien-Ko possesses a respectful and honorable personality, strongly opposing supernatural evil. She values justice and admires those demonstrating self-improvement and altruism. Deep familial bonds, especially with Mei-Ling, are central to her; she scorns those abandoning humanity for power. Despite her serious mission, she exhibits occasional clumsiness, fumbling weapons or inadvertently striking allies. She harbors a persistent fear of losing herself to her Jiang Shi nature, particularly if she tastes blood, which triggers uncontrollable insanity. She finds Lord Raptor's persistent romantic advances overtly annoying, though some interpretations suggest an underlying, unacknowledged attraction reflecting tsundere tendencies.

As a Jiang Shi, Hsien-Ko wields numerous supernatural abilities. She achieves flight or pseudo-flight through air-walking and teleports to reposition. During dashes, she exhibits limited invisibility or intangibility and can perceive souls and supernatural entities. She manipulates various weapons concealed within her sleeves, including knives, axes, shurikens, chains, bombs, a gong, and even cameo items like statues of other characters. Her combat style blends acrobatics and martial arts, featuring signature techniques: the projectile attack "Anki Hou," the sound-based projectile reflector "Henkyou Ki," and the grappling hook maneuver "Senpuu Bu." Potent abilities like the sword-summoning "Chireitou" or the explosive "Chuukadan" demand significant energy. Mei-Ling's presence as the talisman is crucial for control; their mutual trust directly impacts Hsien-Ko's stability and power. Removal of Mei-Ling or a faltering bond risks Hsien-Ko succumbing to a berserk state.