Jin are one of the four dream races and are aetheric and evanescent. When Jin manifest aetherically they find it very easy to masquerade as spirits and sometimes the two are confused. However jin have free will and can completely choose their behaviour. For this reason Jin can be enormously dangerous.
Jin, rather than being born, are created by Jin from the aether of dead Jin. Only a little Jin essence is required to make an entirely new Jin, the essence of the dead Jin is generally formalised through ritual and ceremony. As such Jin do not have sex organs and therefore the roles of mother and father are assigned according to the Jin who nurtures the essence into being (Mother - irrespective of apparent sex of Jin) and the dead Jin who has provided the raw basic material (Father - also irrespective of the apparent sex of the deceased jin).
In the early part of their gestation Jin appear as wisps - small lights that hover about their mother. Over time they become homunculi - small spirits with limited consciousness. Homunculi are bonded to their mother but are definite separate entities the previous stage wisps are not. Eventually Homunculi learn to talk and eventually separate from their mother. Some jin never separate from their mother until it dies.
Cultural taboos often prevent jin from being a mother using the material from their own mother to make a father (although it is not impossible for a single Jin to be both a mother and a father in the course of its existence). The product of such minglings tend to be violent and possess fierce magical abilities that are often destructive and uncontrollable.
Jin live for around 800 years they tend to be wisps for around 50 years, homunculi for a further 150 and then fully developed jin for six centuries before their consciousness destroys itself and they become raw aether capable of fathering a large number of new Jin. The raw aether takes around one century to dissolve, in this time it is expected that one or two Jin will make one or two offspring from the aether.
To have your aether ignored is a great shame for a Jin and is one of the worst things that can happen in a Jin's existence. Great Jin often have thousands of children produced by carefully selected Jin who are keen to take a place in history.
Jin often organise themselves into large "houses" all deriving from a common pool of ancestors, or from single ancestors. Because of their method of reproduction ancestor worship is very important to Jin and they are often deeply connected to their past generations. Jin are not restricted the way that Spirits are and often they find uninhabited planes in which they possess material objects as "skins". The matter of whether a Jin possesses rocks, bodies of water, clouds of vapour, pools of magma or seams of ore are statements about that Jin's identity and often dictate their tribal affiliations.
In more sophisticated Jin civilisations bodies are manufactured for Jin, usually out of metal, wood and stone, the affiliations to other materials become symbolic. Advanced Jin cultures seek to interact with the material beings, particularly the Fae, as if they themselves were material. Whole systems of taboo and ceremony have grown up around these manufactured bodies and some Jin bodies have taken in magical effects which make them into weapons or confer other benefits on the possessor.
It is easy to mistake such Jin for material beings, but to think of them as such is a mistake enemies have made at their cost. Jin are aetheric and must be attacked as aetheric beings. Unfortunately things like salt and iron do not work on Jin as these are the mechanisms of constriction. In order to make themselves express tangibly to the material Jin must learn magic and similarly material beings wishing to attack Jin must also attack magically. Between aetherics death can be a matter of pure domination, one aetheric being tries to constrain and extinguish the other's essence entirely. Older Spirits have the advantage being both powerful and immortal but of two aetherics of equal age the Jin has a natural superiority born of their free will.
It is possible for Jin to possess and control living beings whether sentient or not, in some Jin societies the practice of working in harmony with material animals is a spiritual devotion and a much revered skill. Such Jin often seek to offer service to materials in order to promote harmony between the visible and invisible worlds. It is vital in such cases that the instinct and desire of the animal steed is catered to, if the animal is seen to be dominated or suppressed unnaturally this is seen as taboo and a violation. For this reason a Jin that works with a material animal will often be somewhat beholden to their partner's desires.
In some very rare cases Jin form a symbiotic relationship with sentient materials, very similar to the relationship between a Spirit and an avatar. In these cases the lifespan of both Jin and sentient is increased (if the material is Mortal), if the Jin can form a symbiosis with a sentient Fae the Fae gains much magical power, some resistance against geis, the Jin in turn can survive up to eight times longer having a consistent and incorruptible living form to sustain it. These Jin-Material hybrids are among the most powerful beings in the Dream second only to fully fledged Dreamspeakers but they are exceptionally rare as the partnership requires discipline and emotional bonding to last for the full time potentially available.