Kai’Sa’s bio begins as boring as possible by its own admission. Kai’Sa was a normal, Shuriman child living in a simple village. but as she grew older, around the time she was 10 years old, the world her got more frightening. Void priests would wander from village to village demanding tribute and Kai’Sa’s parents asked her to stay inside.
One day, she and her friends let loose a pen of goats into a nearby canyon as a joke, but the canyon swallowed the goats and awakened the Void beneath their feet. Kai’Sa, her family, her friends, and her entire village was swallowed whole.
Kai’Sa found herself alone in the Void. When she defended herself against an attacking Voidling, she found that its dead heart began to attach to her. As the years went on, this attachment became a second, living skin. She now uses it as a weapon against the hosts of the Void, defending other Shuriman villages from her same fate.
In her short story, The Girl Who Came Back, an adult Kai’Sa speaks with a little Shuriman girl named Illi. Kai’Sa is helping the child defend her village from the Void. Illi, much like a young Kaisa, is brave and unflinching in the heat of the moment. She wants to fight, but Kai’Sa urges her to teach her villagers not to treat the Void as a god and instead treat it as an all-devouring force of nature.
Illi’s villagers are afraid of Kai’Sa. They call her a monster, a thing, a beast that made it back from the Void forever changed. But Illi gives Kai’Sa hope that one day the world above will be worth saving.
Finally, Breach, the Kai’Sa comic adds a little extra flair to the Void hunter. Kai’Sa attempts to save a merchant that has fallen into the Void, but when she approaches the man and offers her help, he pulls a knife on her, afraid of what he does not understand. As she battles Void beasts, the man attempts to run.
By the time he escapes, he is as much of a beast as the monsters below. Kai’Sa, seemingly tired of the same situation happening to her over and over again, puts the zombified man out of his misery and goes back to hunting the creatures that made her the monster that everyone seems to fear.