Very nice. You seem to be getting the hang of that program. Sure its not as good as photoshop, but then again, a composition is only as good as it's master.
06/10 for top and 5.5/10 for bottom (note 08/10 is perfect on my scale, so you did pretty good for a starting piece). The avatar got a higher rating only because it was more symbolic. Meaning it really fit shadow's character; having darkness all around with his hate (in red) emenating from his body. The signature is good, but it really needs positioning. The textures are pretty good and I can tell you tried pretty had on it.
Just remember that simplicity is always the key to victory.
Also remember that there's a thread up there posted just for this purpose and this purpose alone (rating signatures).
The avatar and the image in the sig are not exactly the same. Yes they are the same thing but I added more to the sig image than what I did to the avatar image. I am going to try to add more into the sig and make it better.
Should I close this down? Next time I will just put the next edition of this in the other topic.