The Psycho Duke and I

Diana woke up in a novel as a minor character with a rapidly approaching expiration date. To survive, she deliberately allows herself to be kidnapped by Duke Noah Rottshieldt, a bloodthirsty nobleman from an enemy empire. Though a ruthless captor, the Duke proves to be a surprisingly courteous host. Diana is now enjoying a luxurious and peaceful captivity, even if Noah isn’t fully aware of it. However, he is not as clueless as she believes. The question is: how much is Diana willing to manipulate the plot to maintain her newfound comfortable predicament?