Spirit metal is a substance formed from crystallized granules of qi.[1] Hunduns are made predominantly of spirit metal, and they harvest the natural deposits of it in order to heal and replicate.[1] Humans harvest the spirit metal from Hundun husks in order to create Chrysalises and spirit armor.[2] They cannot make anything using the raw granules from the ground, as they always tarnish within.. Zetian observes that the hunduns take better care of the environment than the humans do, something that surprises her since she thinks it's the humans' planet. Then of course the hundun emperors are begging for them (and their nests!) to be left alone, and one calls humans the scourge of the universe.
Iron Widow is a 2021 science fantasy novel by New York Times best-selling author Xiran Jay Zhao that reimagines China's only female empress, Wu Zetian, as a peasant girl bent on revenge in a futuristic dystopia based on Chinese culture. In this novel, the nation of Huaxia is beset by giant, metallic alien invaders known as Hunduns. The only way to fight Hunduns is to engineer their corpses.. Iron Widow Iron Widow 1 Xiran Jay Zhao PROLOGUE The Prologue introduces Yang Guang, the ace pilot of the Nine-Tailed Fox as he battles a group of Hunduns to protect Huaxia. The Nine-Tailed Fox is a gargantuan mecha-fox made out of the metallic corpses of the alien invader Hunduns. The mechas such as the Nine-Tailed Fox are called Chrysalises and are piloted by a duo of pilots, always one boy.