With most of these, I feel that it's your lighting that's letting you down. There are blown highlights here, harsh shadows there, and unbalanced lighting in other places. While I appreciate that some of these elements are probably what you're seeking in these images, the combination of all of them within the one image just goes too far.
Let's look at the first image, for instance. The lighting is somewhat unbalanced, and possibly poorly placed, which leads to the harsh shadows, which I suspect is a part of what you're wanting in this image.
But you've blown the highlights on both sides of her face, as well as on her left arm - the forearm in particular.
Image 2: the lighting camera right is too far forward, relative to the camera, throwing longish shadows across her face. It's also harsh lighting as well: look at the shadow from her nose, and again, it's too strong, blowing the highlights on her left cheek. Move that light closer to the camera, and pull it back by at least 1.5 effective stops, remembering that as (if) you move the light further from the subject, you are decreasing its intensity.
Image 3: Again, the lighting is a bit too strong, this time camera left: her right cheek is nudging upon being blown. While you may have achieved your goals in terms of how the background has been rendered, I'd prefer to have seen her moved several feet away from this background, and thus you could have thrown it out of focus, where it doesn't compete with the
model for one's attention. And what's with the brighter area on the background just above and to the left of head, and following down to the viewer's left of her face? Is that lighting, or something that you've done in post?
Image 4: Using a wide angle lens for a portrait is a very risky way to go, but you've done well with this imag. Here, we have none of the blown highlights that the other images display, and the lighting here is much flatter, and much more flattering to the
model. I'd like to see the contrast increased just a nudge, and I'm not sure about the vignetting that you've applied, but this is by far the most pleasing of these four images.
Is Viktoriya a friend of your's? Would she perhaps be interested in sitting for a lighting workshop with us? Maybe even with one of her friends?