The colors are unique, but this seems to accent the flame alchemist and his abilities rather well. I'd change the effect the colors have on his skin a little bit (not a whole lot, just a little), and add a little bit more...effect to the color/flames. Other than that, nice job.
The purple bit is gorgeous with the red! I think you should put some more effects, some more layers to make it more balanced, so it doesn't look like he's sleeping in the clouds or something =]
NOW it looks like the sig is really heating up! Looking very great so far! If there's any changes needed, go for it - but keep the heat of the colours, it just really fits the flame alchemist.
I find the purple on the hand a bit odd-looking. And there's something about the text that bothers me...but other than that, I don have much to say.
