Forbidden Fall: Taken by My Ex's Uncle Before His Eyes

An adopted daughter is betrayed by her fiancé and her adoptive sister, then drugged by her entire family and sent to a rumored mad duke as a sacrificial bride. She instead seeks out the duke—who has secretly loved her for years—and forges a marriage contract with him, using his power to settle scores with the earl's family, steadily wrapping the besotted duke around her finger, and ultimately seizing control of the entire territory to become the empire's supreme ruler.