Here is the big pic,

This one is the best mainly because in the big pic you did the next: Shading and highlights are strong, cracks are big and strong, details are big, therefore they can be seen in the icon. The only problem is that the background dulls the image, if you really want to create a fiery effect totally remove the background, start with a glowing dark red and then go adding other colors such as amber, add small sparks and a little bit of yellow for highlights to create that molten core effect.

Thanks for your feedback dude, goes for all the rest of the icon you've commented, I'll restart the rest and improvised this one, apparently this one was the last icon I got hanged into and corrected, now I'll repeat a similar process with the others.

A lot better, change the big pic xD I want to see it

Oh sorry, but I kinda modified the big one/.psd file while it is at its icon size and Saved As, but I didn't save the .psd ^^

Looks pretty good and fits the model. Approved.

It needs a little more brightness.
Looks good anyway.

Looks good, simple and it's useful for whatever purpose you might need it for. Plus (at least in my opinion), it fits with the Warcraft III icon artstyle.