To start with, this version of the image caught my eye more immediately than the before/after version - it is more striking on it's own - although the other version is perfectly valid.
Taking the evil aspect first, I think the eyes are effective - they glow with a rather calculating light, it's cold, and a little mesmerizing, and just a little glittery. And I don't trust people with glittery eyes. The green light is a fairly obvious rendering of eveil - witches skin, serpents, other creatures we inherently see as 'evil'. And as such, it works well. I'm glad to see the pink tones of skin poking through though, as a suggestion of humanity - this does not appear to be an other-worldly evil. Although it would be adhering to convention, personally, I would like to see the lips a little more blood red, and a little less pink - not from a vampiric point of view, just that I think it would be more striking, and as a result, more eye-catching.
I'm also quite taken with the highlight/shadow composition you've used - the highlights on the lower hair work well, where the shadows above are a good contrast to the glow of the face.
Now, in relation to hair, I'm wondering if the marks around her (screen) right eye are meant to be hair, scars or bloodvessels?I think if they're hair, they're possibly a little too fractuared, but if they're scars, then maybe they could be bleded in, just a little - consider how scars look on the skin/ And having mentioned bloodvessels, I wonder if it would add to those rather freaky eyes to bring in a few faint vein lines around the under-eye?
Earlier I mentioned serpents, and I do think, whether it was intentional or not, that the porous nature of the skin backs that association up - I'm not sure which technique you've used to do that, but it works very well with the green tinge.
The clarity/sharpness of the face works well contrasted against the slightly softer neck.
From a compositional point of view, I think the line of the face is nicely mirrored in the curves of the hair. And call me picky, but I'd love to see what this looks like as an oval image rather than rectangular - I just think it would really bring it out that bit more.
None the less, an eye-catching piece of work. Well done.