In the beginning, say the sages of the Middle Kingdom, the universe split into two halves. One of these halves was the bright, active Yang; the other, the dark, negative Yin. Kuei-jin are creatures suspended between life and death, and thus they have a measure of Yin and Yang.
The character sheet displays two separate Chi Virtue tracks. The first, the permanent rating (the dots), measures the character's personal leaning toward positive or negative energies, as well as her degree of control over the energies she ingests. This rating is used whenever the text calls for a Yin or Yang roll. The second track, the squares, measures how much temporary Yin or Yang (otherwise known as Chi) the vampire has ingested. Temporary Yin or Yang may (and often does) exceed the vampire's permanent Yin or Yang rating; this condition is known as Chi imbalance, and can lead to deleterious side effects.
Permanent Yin and Yang serve as rough measures of a character's personality. A character with a high Yang rating is likely to be energetic and prone to emotional extremes (of happiness, anger, even fear or sadness); conversely, a character with a high Yin rating is likely to be icy, calm, cynical, and somewhat pessimistic, possibly even morbid. In most cases, a high rating in one Virtue necessitates a lower rating in its opposite — it is difficult to be simultaneously calm and emotional. However, vampires of great enlightenment (6+ in a Dharma rating) have learned to assimilate and harness their inner dichotomies; thus, one might well find very high Yin and Yang scores coexisting in the same bodhisattya.
The Yin Virtue quantifies the character's attunement to dark, negative energies. It is used when resisting the fire soul, when powering and channeling Yin-aspected Disciplines and when dealing with ghosts and other Yin-spirits.
Vampires with high Yin scores commonly master Disciplines relating to death and the manipulation of negative forces. Because such Kuei-jin are repositories for so much negative energy, mortals often find these Cathayans repellent or creepy — although some mortals, ones with high Yin energies themselves, find themselves drawn to high-Yin vampires. Vampires who have imbalanced themselves with Yin tend to appear corpselike or even putrescent; these undead are referred to as ch'ing shih.
Kuei-jin have two Yin ratings. The permanent Yin rating (the circles) measures the character's control over negative energy. The temporary Yin rating (the squares) measures how much Yin Chi is actually in the vampire's body. If the character ingests much more Yin than he is capable of handling, a number of ill effects may result (see "Chi Imbalance,").
• Fire Nature —First and foremost, the Yin Virtue is the Trait used when rolling to resist fire nature. Vampires with high Yin are simply too cold and detached to be overly affected by rage.
• Ghostsight — By spending one Yin point, Cathayans can attune themselves to their Yin, allowing them to view Yin's marks on others. This power functions similarly to the wraith ability of Deathsight, and it lasts for an entire scene.
Ghostsight allows the Cathayan to view creatures from the Yin World; such creatures include wraiths, Spectres, and others. To do so, the Cathayan must concentrate for three turns and roll Perception + Occult (difficulty of the local Wall + 2).
A Cathayan using Ghostsight can scan objects or living prey (undead and Risen count, ghosts don't) for structural weaknesses. By spending three turns in concentration (no attacks, no movement faster than walking speed) and rolling Yin + Medicine (living) or Crafts (inanimate) versus difficulty 8, the vampire can make an "atemi" strike against the object, inflicting one extra level of damage per success. This technique is good for a single physical attack; once the attack is made (hit or miss), the vampire must reattune herself to the object if she wishes to make another focused strike.
The vampire can study the mystic blotches caused by Yin's erosion. In this manner, the vampire can detect and analyze any damage, disabilities or illnesses from which the target suffers. Doing so requires a Perception + Medicine roll (difficulty 4 to 8, depending on the nature of the ailment). Success allows the vampire to make a rough diagnosis of the target's health, level of injury, and whether or not the target suffers from disease, blood loss, etc. A vampire without high levels in the Medicine Knowledge probably cannot recognize the precise ailments of the target, only that he is "sick," "feverish," "weak," and the like.
By using Ghostsight on a broken inanimate object, the vampire can make a Perception + (appropriate) Crafts roll (difficulty 4, to 8, depending on the extent of the damage). Success allows the vampire to analyze the damage and gives her some idea of how to repair the item.
Yang, the opposite of Yin, is the bright, active spark coursing through most living beings. It is Yang that gives Kuei-jin the strength to undertake the Second Breath — but it is also Yang that fuels the vampires' ravenous hunger. In some ways, Yang is the driving force that impels the Kuei-jin to come back and fight on night after night. Without Yang, the Kuei-jin say, they would simply be... dead.
Although Yang is "positive" energy, this term has slightly different connotations among the undead. Yang Chi is the fuel vampires use to advance their ends — whether these ends are "good" or "evil" depends entirely on the vampire in question. Yang is used when resisting terrifying situations and when taking action.
In contrast with their ghoulish Yin counterparts, vampires with high Yang seem more human. They are the undead who rise from the grave to avenge families, settle old scores or reunite with loved ones. They love walking among the Middle Kingdom's teeming throngs, figuratively and sometimes literally drinking in the energy of the crowds.
However, no matter how much Yang a vampire consumes, it is, at best, a parody of life, and stolen life at that. Vampires with high Yang like to pretend to be human, but so it is, exactly — a pretense. When their vampiric natures inevitably come to the fore, their disappointment often prompts frenzies far more vitriolic than the ones of their more phlegmatic cousins.
• Healing — Yang Chi can be combined with the vampire's blood and delivered to others as an elixir of healing. Each point of Yang Chi heals one normal Health Level.
• Lifesight — Just as Cathayans can view Yin's traces, they may also duplicate the wraith ability of Lifesight. By spending one point of Yang, the vampire may attune himself to the life-flows around him for one scene.
When two (or more) beings encounter each other, the emotional auras surrounding them "flare" for an instant; vampires who attempt to read this aura (Perception + Empathy, difficulty 9) can gain insight into the true feelings of the observed creatures. Thus, if two rival business magnates chummily greeted each other at a party, an astute Kuei-jin could detect the spark of loathing and envy that momentarily flared between them. (This power is best reserved for mortals; it is considered a dangerous breach of etiquette to use it upon other shen, though the Kin-jin and other such barbarians may, of course, be scrutinized at will.)
The vampire may detect overriding emotional passions in mortals. By concentrating on a particular emotion and rolling Perception + Yang (difficulty 9), the vampire may "home in" on that emotion. The range of this power is 20 feet times the vampire's Perception score. Besides its obvious use in hunting (e.g., attuning oneself to lust in order to determine which mortals are easily seduced), Lifesight allows vampires to find vessels with great amounts,of emotional energy. For each success on the Perception + Yang roll, difficulties of the vampire's hunting rolls are reduced by one. :
Finally, the vampire may attempt to detect creatures from the Yang World, including spirits of the sort known to werewolves, as well as other beings from the realms known in the West as the Middle Umbra. To detect such creatures successfully, the vampire must concentrate for three turns and roll Perception + Occult (difficulty of the local Wall + 2). Once seen, spirit creatures remain visible for the duration of the scene (More information on spirits here.)
• Wave Nature — Yang is the seat of bravery. The vampire uses his Yang Trait when rolling to resist wave nature.