Jin is a teal-blue, amorphous creature with a round and lumpy body bearing his facial features, two extra eyestalks above his normal eyes, a vertical series of red lumps on the top of his body, and two pipelike appendages on opposite sides of his body. Gathered from his appearance in the Eastern Mind opening screen, he also has two legs protruding from the underside of his body.
Jin's purpose is to be born in the Land of Desire, but during the introductory cutscene for Jin's life it is revealed that the reincarnation is unsuccessful and Jin's body melts while attempting to carry the weight of Rin's soul. As a result, there is no gameplay or mission for Jin and the only requirement to earn his nameplate is to reincarnate as him.
Jin's name is the sixth syllable of the Kuji (九字), a series of nine syllables. Each syllable has its own symbol, mudra (hand sign), mantra (utterance/prayer) and mandala (visualization). The syllables in order are Rin (臨), Pyō (兵), Tō (闘), Sha (者), Kai (皆), Jin (陣), Retsu (列), Zai (在) and Zen (前). The mudras, mantras, and mandalas put into practice for ritual or meditation purposes is referred to as the Kuji-in (九字印), or "Nine Hand Seals". The Kuji-in has roots in Hinduism and is used in a wide variety of practices including Shinto, Buddhism, Taoism, Ninjutsu and schools of Japanese Esoteric Buddhism such as Mikkyo, Tendai and Shingon.
The kanji "jin" (陣) can mean "in formation/position", "reading of thoughts" or "awareness".