As the final note echoed, the theater fell into a deafening silence. Then, a single pair of hands clapped from Box 5.

Elena looked in the mirror. The girl who had arrived at the theater that morning was gone. In her place stood someone who understood that in 1938, sometimes you had to dance with the devil just to keep the music playing. To help me refine this story into exactly what you need:

Should the be a supernatural figure or a human villain?