Dien Ch'ing was a Cathayan Chaos Cultist who posed as an ambassador of the Dragon Emperor of Grand Cathay to the court of Emperor Karl Franz.[1a]
Referred to as a "Celestial," in the Empire, Dien Ch'ing was a servant of Tsien-Tsin, Lord of the Fifteen Devils, known as the Chaos God Tzeentch in the Old World, who posed as a servant of the Monkey King. At an unspecified point of time, the Monkey King had expelled him from the Cathayan Empire, causing Dien to bear a grudge against him.[1c]
Having killed the real Cathayan ambassador as he crossed the Dark Lands, Ch'ing hoped to lure the army of the western Empire to enter the Dark Lands where it would fall to an ambush that would leave it vulnerable.[1a]
Ch'ing had served his divine master for his entire life, travelling across continents to further the Invisible Empire. He was well-schooled in the various martial arts of the Far East.[1b] During his travels, he had been present at the Second Siege of Praag, where he had witnessed the infamous Dwarf Slayer Gotrek Gurnisson in action.[1c]
Dien would later conspire with the mutant revolutionary Yevgeny Yefimovich, with whom he had previously worked at Zhufbar, to incite the people of Altdorf against Karl Franz.[1b] During the Great Fog Riots, he lured Crown Prince Luitpold into a brothel, where the revolutionaries hoped to kill him, but this plan was foiled.[1d] After the riots had failed, Ch'ing vanished.[1f]
The post of Cathayan ambassador to the Empire was next filled by Yabo Chao.