Hi there! I start this model a long time ago and just now I managed to finish it. I think this is a famous character in the Blender community, the concept art and model sheet was developed by David Revoy and shared under the Creative Commons license. So I’ll do the same here sharing the blend file and I hope I could help you to learn something new from it.
I think the pose is a little weak though, with the amount of blur it looks like he is going face downwards, which would look nicer if he had one of his legs flexed as if he is going to kick someone. Not sure it makes sense, good work!