With demon blood as ink and the Hundred Demon Codex as her scroll, she can paint their forms and seize their powers. Jiang Yuechu wakes one day to find herself a young girl in the golden age of Tang. Beneath the moon of Chang'an, splendor and decay coexist, immortals and Buddhas have vanished, and demons roam free. Luckily, slaying creatures raises her cultivation; by painting each demon into her codex, she turns them into her own strength. From the Tiger Mountain God's domineering blade arts to the Azure-Faced Wolf Lord's predatory gaze; from the White Flood Dragon's water control to the Black Mountain Bear Lord's earth-shaking might! Sometimes Jiang Yuechu worries—why does she keep gaining more and more powers?