I've seen enough hentai to know how this might end up...

On a serious note, though, it's a great job! Lots of detail!

So, these are all pencil on colored paper? They look amazing. Have you considered adding some white? You would get an even more #D effect if you added some touches of white.

Agreeded. these are incredible pieces but the addition of a little white may really add to the dramatic affect of the scene.
Not on all of this style of drawing, I love them like they are, but perhaps as an experiment on a few pieces.

I've seen some drawings of monsters on colored paper, white pencil was evidently used. Since I'm not similar to their drawings, I'm original There's a danger that the drawing can gain effects, loosing serious atmosphere. I mean that it may turn into something less realistic like design and manga. But I'll specially create a new drawing to see, what the white color can really do.

adding white will make it MORE realistic if done right!

I assumed to add some white color, however, I also felt disadvantages of it. It would make the work even more enduring. Also I would need a reliable tool that draws with white color. The drawing may become insufficient. It's when you look and understand that there are should be not onle white, but also red or green or other colors. But I will try to add white color as an experiment.

White Prisma Color should work for you on something like this.

http://www.furaffinity.net/view/6822863
This is much less detailed than your work, but it is just black and white on a colored board. This is to give you som idea what I mean.