Iron widow

The boys of Huaxia dream of pairing up with girls to pilot Chrysalises, giant robots that battle aliens that lurk beyond the Great Wall of China, no matter that the girls 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 when it becomes clear that she is an Iron Widow, a rare kind of female pilot who can sacrifice males to power up Chrysalises instead, she determines to use her and her male partner's combined strength to force her society to stop failing its women and girls. Or die trying.