The Kuei-Jin are the vampires of Kindred of the East. The term is a portmanteau word consisting of the Mandarin word for ghost (kuei) and the Japanese word for person (jin). It is a relatively recent construction designed to indicate the commonality of the undead condition throughout the Middle Kingdom.
The term Cathayan is often used by Western Kindred to refer to the Kuei-Jin. The term is borrowed from the classic name for China, Cathay. It is perceived as offensive by the Kuei-Jin themselves.
History
The Kuei-Jin are the corrupted descendants of the Wan Xian, the "Ten Thousand Heroes" chosen by the August Personage of Jade to guide and protect the universe in ancient history. The Wan Xian were originally chosen by tests of skill and courage, and fed on the ambient chi of the universe. However, they fell from grace, learning to feed off of the chi of living beings and corrupting the tests of worthiness. Their children, the Jin Hai tried to keep them on the path of righteousness, but were eventually killed for their presumption.
As the blood of the Golden Children cooled, the August Personage pronounced judgement on His former champions. He cursed them to live as undead, unable to acquire chi except from drinking the blood of the living, and to exist in a brutal mockery of their former state. He revised the tests so that the former heroes and champions were replaced by criminals and murderers who escaped from Hell itself. Then He left the Wan Kuei alone to contemplate their crimes.
Since that time, the Kuei-Jin have sought redemption through enlightenment. There are many paths initially ascribed to Xue, the Grand Arhat of the dead. However, the road to the Hundred Clouds is long, and the Kuei Jin are ultimately forced to stay on the Wheel of Ages as history slowly grinds towards the inevitable victory of hell and the rise of the Demon Emperor.
Creation
In the Middle Kingdom, all creatures are belived to have two souls: a Hun, or higher soul, and a P'o, or lower soul. In general, the P'o is a brutal aspect of a person, while the Hun is more refined, intellectual and impotent. When a person who has led a less than exemplary life dies, that person goes to Hell. There, the P'o and the Hun are generally shredded for chi, unless they can strike a deal and find a way out.
On the rare occasions they can, the body takes its "second breath" and rejoins the land of the living as a cannibalistic demonic hellbeast. If not caught, these creatures will go on killing sprees and rampages of destruction - which is why the capture and civilizing of infant devils is a critical part of Kuei-Jin society. All Kuei-Jin begin in Hell and then graduate to a mad cannibal in a human body; it is only through discipline and whipcracks that they can move above that level.
Physical Nature
The Kuei-jin are physically akin to the Risen, in that their physical bodies are powered by mystical energy and that energy serves to heal them. Unlike the Risen, who rely on pathos to power them, the Kuei Jin use chi. Depending on the type of chi used, a Kuei Jin's body will have different attributes - ranging from a low-energy corpse like state, to a feverish state close enough to life that they can create new life. Apart from being faster, stronger and tougher, a yang aspected Kuei Jin appears to be a living human being.
Kuei Jin are less tied to their bodies than might be expected - because they are spirits wearing bodies, they can take an enormous amount of damage, including a little death that wipes out the body and forces the Kuei Jin to seek out a new host. There is a subspecies of Kuei Jin, the Yulan Jin who do this on a regular basis.
Kuei Jin are effectively unliving chi batteries; they need and hunger for chi the same way that the Kindred hunger for blood, and they need no other sustenance, although they take more pleasure from food and sex than the damned do. With the right chi, Kuei Jin can even withstand the sun for a short period of time.
Spiritual Nature
The Kuei Jin have an awakened P'o which seeks to make them fail. This P'o behaves like a wraith's Shadow and can temporarily take over the Kuei Jin. As a result, Kuei Jin are constantly struggling against a far more intelligent and wily opponent than the beast that bedevils the Kindred.
More importantly, Kuei Jin are creatures on a spiritual trek. They have been granted a second chance by Heaven, and must earn their redemption in this new life. To do so, each Kuei Jin subscribes to a Dharma. Each Dharma outlines a different view of the universe and the means towards achieving enlightenment. In addition to spiritual comfort, enlightenment brings strength - as a Kuei Jin advances in his dharma, he learns to feed off things besides blood, his ability to manipulate chi increases and his abilities can achieve new heights.
Organization
Since before recorded history, the Kuei-Jin have been divided into a variety of Courts that cover various geographic regions. The five greatest of these courts comprise the Quincunx in China, but there are also the uji of Japan, the Golden Courts of Southeast Asia, the Green Court of Korea and the Infinite Thunders Court of the Indian subcontinent.
Unlike the relatively anarchic Kindred, Cathayans have an elaborate society and governmental system which each vampire is expected (or better yet, required) to join. As a result, the training for a Kuei-Jin is much longer than the expected training period for the undead, and the Kuei-Jin are quite willing to execute any prospective candidate who fails their tests. In the modern era, this training is even more extensive to rub off some of the western taint, a newly reborn vampire can expect to learn etiquette, politics, the use of disciplines, silent feeding, poetry and the elaborate Kaja script.
Cathayans are bound together in wu, circles of Kuei-Jin mystically linked to each other and a guardian nushi. A Wu is the fundamental social unit of Kuei-Jin society, and many Wu have famous histories. Traditionally, Kuei-Jin were expected to join an existing Wu.
Outside of the wu system (which intentionally transcends dharmic boundaries in order to promote harmony), Kuei-Jin will also obey the strictures of their dharmas. Each dharma has its own methods of enlightenment and internal hierarchy, ranging from the extremely formal testing procedure of the Devil Tiger dharma to the individualistic teaching style of The Path of a Thousand Whispers path. Each dharma is a religious school, one that is followed with intense devotion by the Wan Kuei, as the alternative is the madness of the chih mei. There are dharmas outside of the fivefold path of Xue, although these are considered heretical and are followed by a vanishingly small number of Wan Kuei.
Background Information
Ostensibly, the name "Kuei-jin" is supposed to represent the two major cultures involved, with the Mandarin "demon" (kuei) and Japanese "person" (jin) being combined into a single name. Unfortunately, this would only make sense with Western audiences, and wouldn't make any sense at all with the alphabets of the cultures in question.
The same root alphabet is used for both Mandarin Chinese and Japanese. A Chinese speaker seeing 鬼人 (or 人鬼 read right-to-left) would read it as "kuei-ren," while a Japanese speaker seeing the same characters would read it as "oni-jin." While the meaning (demon-person or ghost-person) remains the same, there is no way to write the phrase in a manner which would be read as "kuei-jin" by either culture, unless using a Western alphabet.