I like the way you keep trying out new tihngs Tosiek and it's good that you do that. I admit that the sig isn't that great for you but with a bit more work it could be really good Huntelaar sig.
I haven't really seen you use grunge before but I can definately see what you tried to do, create an explosion. I think what you need is that certain 'flow' through the sig, it needs blending really. The render is where it gets let down, it's been desaturated too much. What you need to do is to sort out tha render again and then over the top of all the layers, choose like the main colour and fill a new layer with that colour and set it to about 20-30%. You could also duplicate that layer and try a new blending option too like 'darken' or 'difference' but maybe set the opacity lower.
As for the brushing I think you need someting link the small explosion next to Klass (which is impressive) with the space to the left making sure there's a nice sense of directionality towards the left to keep with the explosive theme. Also have a nice mix of dark smokey firey clours, with the brighter firey colours so there's a nice depth.
Anyway I hope them tips are helpful for you mate