What's the story?
A lonely demon born with a natural hunger for blood and power has one way to cope with her purpose:
Manipulate, kill, feed, repeat.
This coping mechanism seems promising as she is the only one of her kind on this human thriving world; an endless supply of innocent blood.
But what happens when she finds a demon like her? And he tells her to stop what she has been doing for centuries--all to save the land she kills on?
How can one willingly choose to stop surviving? How can one against her nature, especially if villains aren't meant to be heroes.