Character is too important a story element to let go at combining disparate elements. Even if you use non-stereotypical outer aspects of those who populate your tales, please also remember to give these beings some depth. Assuming that you, as a real human soul, have certain musings and motivations beyond the superficial, so should your story's cast. Make us believe that there is a strong enough reason here. Give us a mindset that will chill us, if you like, but don't allow the readers' eyes to roll upward in skepticism or disgust.
People are interesting.
Characters that aren't true to life are boring. Plot elements should be logical. Logical means that a person with an everyday education might reasonably assume that a character such as you describe, of this social class and gender, and in this setting, will take the action that you, the author, have ordained. Too often a plot wrinkle rests on the author's desire to wrinkle the plot and nothing more. Plot has to move from the foundation of what has been set in motion at the start.