After Cinder’s revelation, Kai tells Cinder sadly that he has to marry Levana, even though he knows she’ll likely kill him or start a war anyway. In desperation, Cinder kisses Kai and says as she pulls away that perhaps Levana will not accept his proposal when she finds out that Kai is in love with Cinder. Levana, standing nearby, says she doesn’t care if Kai is in love with someone else, but she does care that Cinder is Lunar and a shell. Levana insists that Cinder be taken into captivity.
Just as Cinder is risking her well-being by warning Kai of Levana’s plot, Kai also resolves to make a self-sacrificing choice, demonstrating how much Kai since his initial hesitance to give up his freedom and take over his father’s role as emperor. He wants to put the health and safety of his people over his own life, potentially saving millions of lives.
A guard grabs Cinder, but Kai protests, saying that Cinder isn’t Lunar. Warnings flash on Cinders retina display as she feels a spike of adrenaline. She tells Levana that if she had not been brought to Earth, she would be a slave under the queen. Kai’s face falls in shock, but he tells Levana that he doesn’t care where Cinder was born—she’s a citizen of the Commonwealth and will not be arrested. Levana asks Kai if he’s prepared to bargain for Cinder.
Even though Kai is devastated by Cinder’s deception about her identity, he still overcomes his bias against Lunars in an attempt to protect Cinder. Even though he, like most other Earthens, is prejudiced against Lunars, he now knows and cares about someone who is Lunar. As a result, Kai is much keener to protect a Lunar from Queen Levana’s oppression.