The demons look fine as shadowy shapes, it lends imagination to the viewer.
Of far more concern is the rest of the composition. The face in the upper left corner is too close to the edges. Should this piece be worth keeping and displaying, you could not frame it properly without ruining it. You should always try to have about 1/2 to 3/4 of an inch border on your pieces as room for framing. Paint it, just don't put any details there.
Next is the nude figure. The anatomy isn't bad, but the lower legs need work. Your biggest concern here is the light source. You show a light source emanating from her left armpit and another below her bent left shin... Is that your intention? What is the source of the glow from behind her? Next, why is she floating around like that? Is she supposed to be standing on something?
Did you do any preliminary sketches before starting this piece? What is your intended scene here? Where IS your light source? What is the purpose of the head in the corner? It's not looking at the rest of the picture, and too much is cut off to give it any character...
This piece really needs a lot of work to approach any kind of completeness, but it is an interesting study piece if nothing else. You should try roughing out a composition of what you intend to create, including mood, main compositional elements, light sources and color schemes before starting, so as to save a lot of painting over.