Transmigrated as a Frail Girl in the Apocalypse, I Become a Big Shot with the System

Lu Xiaochen, a college student in her previous life, transmigrates into a book. She was an orphan in her past life, but things are even worse this time: the apocalypse is only days away! The zombie world is terrifying, but luckily, her cashback System helps her cut through every obstacle! Zombies call her Sis, the Zombie King calls her Boss, and humans call her their Lord! I opened this mountain, I planted these trees, and I rule this road!