For starters the impact behind this piece is amazing. It really captures the energy. Some of the textures seem a bit overboard but nothing is too distracting. I feel you found a good balance between textures and rendering. I really like the composition but the one thing that bothers me is the bright light to the left. I find myself traveling around the piece and then find my self staring into that spot. From reading the description I can understand there is a good reason the light is there. A good thing to remember is the eye is always drawn to the place with the most contrast.
The anatomy is spot on and the facial expression makes it even better. It always does my heart good seeing anatomy done right. I also really like the color scheme that was used for this piece. The dark green background really makes the red pop. I think even adding some blue in the background would make the orange pop in the explosion that much more.
Looking at your other works I can tell this one has a less rendered quality to it, but in all honesty you made it work. I will be watching your work because it's inspiring as a digital artist.