I admire your paint control, everything looks nice and tidy.
Although as Jimsolo said your painting will benefit greatly when you start thinning down your paints.
The colour choices are rather nice but with the use of both the Green and the Red it ends up looking a tiny bit like a Christmas tree...Try to tone down these colours a little or use them a little less. Otherwise your mini can look like a Christmas Decoration.
Black is a difficult colour to paint and can look a little flat if it is not highlighted or shaded properly.
It takes a lot of practice but black is much easier to master if you don't use black at all.
Start off with a really dark grey or in your case you can add a tiny bit of green in for effect.
After that is done highlight by adding successive amounts of grey to your mix.
Wet blending and hundreds of other techniques also look great but take time to master.
I'd say search for some articles online for how to paint Black, they will help you out greatly.
Regardless he is a nice mini that will stand out on the battlefield!