The boys of Huaxia dream of pairing up with girls to pilot Chrysalises, giant transforming robots that can battle the mecha aliens that lurk beyond the Great Wall. It doesn't matter that the girls often die from the mental strain.

When 18-year-old Zetian offers herself up as a concubine-pilot, it's to assassinate the ace male pilot responsible for her sister's death. But she gets her vengeance in a way nobody expected—she kills him through the psychic link between pilots and emerges from the cockpit unscathed. She is labeled an Iron Widow, a much-feared and much-silenced kind of female pilot who can sacrifice boys to power up Chrysalises instead.​

To tame her unnerving yet invaluable mental strength, she is paired up with Li Shimin, the strongest and most controversial male pilot in Huaxia​. But now that Zetian has had a taste of power, she will not cower so easily. She will miss no opportunity to leverage their combined might and infamy to survive attempt after attempt on her life, until she can figure out exactly why the pilot system works in its misogynist way—and stop more girls from being sacrificed.
 
Bonus Summary by the author:
 
Under siege by monsters beyond the Great Wall like that shitty Matt Damon movie, except the monsters are Cybertronian-like sentient machines, a society that has the fashion, social customs, and beliefs of Ancient China but futuristic tech fights back by pulling a Neon Genesis Evangelion and rebuilding their very invaders into giant mecha. A boy-girl pair in their teens, because of course they have to be teens, pilot the mecha Darling in the Franxx style, except in a much more sensible position (he hugs her from behind). Under command of human pilots, these mecha take on forms inspired by East Asian myth creatures and transform like Transformers through Digimon-esque evolution lines that get more humanoid as you go on. The pilots physically embody them, so it’s more Attack on Titan rules than Gundam. Oh, and they blast qi attacks, so the battles honestly read like a bunch of furries engaged in a Dragon Ball Z fight, and that’s no one’s fault but mine.