Too wide for a signature, background is too bland, I'd try adding some grunge brushes, or stylize it with some C4D or multiple motion blurs of render on different blending options. Render also needs more blending which is usually fixed while working further on background and making adjustments when re-applying whole image to create further effects.
I don't know your experience with the software so maybe I'm just speaking crap you have no idea what it is, but basically try to spice up background, main render shouldn't stand out that much from the BG.
And finally the text style doesn't match, the yellow glow doesn't fit the rest of the colors other than a bit from the render.
On the bright side the concept looks decent, with the swordy things on the back, if the render was blended into the BG (which would make it look redish) it would look much better.
It's not bad for a first try though.
Here's basically what I mean with blending and 60 seconds adjustments (and with disadvantage of not having the layers you have to work with Dx)
[Image: http://i50.photobucket.com/albums/f302/protoman206/Banner.jpg]
V
[Image: http://i11.photobucket.com/albums/a178/letixferrance/Banner-1.png]
or render retaining more of it's original color + slight bloom effect for blending (looking it at it now I probably left it at too much opacity and could fix some of that white smudgy feel with selective color adjustments + masking to avoid messing with the render)
[Image: http://i11.photobucket.com/albums/a178/letixferrance/Banner2.png]
edit: like this maybe
[Image: http://i11.photobucket.com/albums/a178/letixferrance/Banner3.png]
Major problem is still the text, just try different stuff, a teacher of my design class once told me that one of the keys on designing is to never be pleased with your own work, try different settings, adjustments, fonts, effects, and experiment until you find the outcome you are the least displeased with. Never being pleased with your work is a little far-fetched of course, but it's just to make a point that you should always experiment =p
Anyway, notice how colors start to blend better, the render doesn't look that out of place anymore, which I believe makes it much better. And if you want it to retain more of it's original color then toning down the opacity of the adjustments would solve that problem.
Basically what I used back there was applying whole image on a new layer (image > apply image) slight motion blur , blending on overlay low opacity. Another layer of whole image touching levels (ctrl+l) and then trying different blendings. Then making curve and vibrance adjustments layer to adjust the lighting of the image and a gradient map of black and white on multiply (on very low opacity!) to reduce some of the out of place brightness around the image.