Bai

Molecular Manipulation: She possesses the ability to generate and discharge electricity through conductive media (i.e. she cannot discharge it through air or concrete) at sufficiently high amounts to kill grown men. The power is more than simple electric shocks; she can alter matter (particularly electrons, which is the source of electricity) on the quantum level. She is capable of special particle luminance, meaning she can change molecules similar to how humans are changed into contractors. This ability is also one of the more, if not most, powerful and coveted powers known as it is the only one capable of altering gate particles at will. She used this power to fuse with Hei, which gave him his power.

Obeisance: Her obeisance is sleeping.

During her brief appearances, she is also shown to be a loving sister, giving her power to Hei, and giving him advice when Hei had to make a difficult decision at the war on Hell's Gate. Even as a child she spent most of her time with Hei, this didn't change when the two of them grew up, as both joined the Syndicate.

Bai has black hair tied in a ponytail, with two bangs framing the sides of her face.

Bai and her brother Hei witnessed the initial meteor shower. When seeing the shooting stars, Hei asked her to make a wish and it will be granted. Soon after one shooting star became a meteor shower. She became a Contractor and joined the Syndicate with her brother. Bai is the Contractor responsible for the disappearance of Heaven's Gate five years prior to the story's setting and had since vanished. The Messier code BK-201 belongs to her star. During Heaven's War in South America, Hei was constantly together with Bai during their many operations, acting as a bodyguard of sorts. It was for Bai's sake that Hei originally joined the Syndicate. When the Heaven's Gate disappeared, Bai's power became Hei's, because—according to Amber—she continues to exist within him. Hei himself remains oblivious to the fact, until the very end. Her real name is revealed at the end as Xing.