This is a good dynamic, and Punchy image. I like the angle you've used (with the character coming directly towards us) and I think the colouring technique is working fantastically well! - I especially love the spattery effects of the blues and whites coming off the figure. He reminds me some how of a blue Ghost-Rider, only flaming all over instead of just the head!

Here are a couple of points that could help to push this image even more, to make it a tighter, more professional looking illustration;

As I've already mentioned the pose is nice and dynamic, and the foreshortening is working well for the most part. When roughing out poses it's a great idea to think about keeping the silhouette as strong and interesting as possible, for example bring some hard corners into those knuckles to make them really punchy, and perhaps bring a bit of the foot out a touch to make the pose look considered/planned all the way down, instead of just tapering out towards the bottom (as it does currently). - Here's a great example of strong silhouetting; [link] - because of that tiny suggestion of a foot in there you could tell what this pose was just from the outline, even without any of the internal detail.

Like I said initially, I really love those dots and spatters, it's a brilliant effect, however I can't help but think there's some inconsistency between the approach to the head and hands, there's a lot more grit and detail about the head, which has the effect of pulling the viewers eyes there initially which is effective, but the lack of spatters and detail around the hands is then odd, because they're closer to us, you'd expect to see more details there. - Perhaps using more white spatters coming off from the hands could help this, without it all blending in to one big mess of spatters! - I'd also suggest using some reference photos for drawing tighter/more anatomically correct fists, since these look a little simplified/basic in comparison with the skull.

In terms of improving the overall composition/impact of a piece like this, I suggest that this punchy pose could be enhanced even further by making clever use of the space it's occupying. At the moment your canvas is pretty close to a square, but if you made it taller/thinner, it would contrast with the layout of the figure. Adding a some kind of zoomy/abstract/motion-blurred colours to the background could help to add some movement to the piece, which currently is a little static against the solid black background (for example; [link])
- tilting the character off of the absolute horizontal could help this too.

Also, if some background was added then bringing in the solid black as borders on two or more sides, but offset and wonky could really help to make the image more edgy (examples; [link] [link]) - hope you don't mind the examples from my own work there, they're just the first two I could think of!

... of course these are all just suggestions to think about for future pictures, as I started by saying this is a perfectly good image in itself and doesn't need "fixing" - if you wanted to try playing with any of these ideas it could be cool to see how this illustration changes, but hopefully the suggestions will be useful for future pictures even if you choose not to revisit this one.

- Keep up the great work!