Iron Widow Series by Xiran Jay Zhao

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... moreThe 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. less

After suffering devastating loss and making drastic decisions, Zetian finds herself at the seat of power in Huaxia. But she has also learned that her world is not as it seems, and revelations about an enemy more daunting than Zetian imagined forces her to share power with a dangerous man she cannot simply depose... moreAfter suffering devastating loss and making drastic decisions, Zetian finds herself at the seat of power in Huaxia. But she has also learned that her world is not as it seems, and revelations about an enemy more daunting than Zetian imagined forces her to share power with a dangerous man she cannot simply depose. Despite having vastly different ideas about how they must deconstruct the corrupt and misogynist system that plagues their country, Zetian must join this man in a dance of truth and lies and perform their roles to perfection in order to take down their common enemy, who seeks to control them as puppets while dangling one of Zetian’s loved ones as a hostage. With political unrest and perilous forces aiming to undermine Zetian at every turn, can she enact positive changes as a fair and just ruler? Or will she be forced to rely on fear and violence and succumb to her darker instincts in her quest for vengeance? less