Transmigrated as Cannon Fodder: Why Did the Female Lead Call Me Sister

A world champion boxer who had won the Boxing Champions League gold trophy five years in a row never imagined her life would end so miserably. She had expected to face either heaven or hell after death. Instead, she woke up inside an internationally famous fantasy novel she had once read out of curiosity. As if that weren't bad enough, she had transmigrated into the body of the story's villainess—the woman who had made the female lead's life a living hell. Eh? {°•°} Why is the female lead calling me sister so intimately?