I liek the shiny, mind if I make my own version to show you how to shade it, or should I not?
EDIT: If you did not want me to do this please notify me, but I'm just trying to help you out.
Here is my version:

I know it's not in the center but whatever... I'm not the best spriter either but at least I'm trying to help. I positioned my light source to his upper right (our left) to give it distinct areas of light. I also shade under things that may stick out or can cast shadows such as his mouth and head. Since his light source is the left, we shade the most on the right, and it will be darkest at the most bottom part because it is also shining from above. Here is a list of things wrong with your original sprite...
1)When I zoomed in, there were too many amounts of colors trying to shade. you don't need to have every single shade in between shades since most DS games cannot hold that many colors. I had to pick out the most contrasting colors from each shade just to get the perfect color scheme.
2) The white background was also many types of white. (I'm guessing you got these colors from Tyranitar and got it from a Google Image Search and picked out one that wasn't a PNG or it was a snapshot of one.)
3)If you were putting these into hacks, they would be too small, the GBA games have specific pixel dimensions being 64x64 for every Pokemon. The DS games however have an 80x80.. You can easily fix this by going to IMAGE, ATTRIBUTES, and then I forgot lol.
4) Well this is actually a good thing, you had a concept, or at least it looks like one, you didn't jump into large dragon things that would suck like most Spriters who make it nowhere do on PC. You seemed to keep it simple yet stylish.
I hope I helped,
I am Scizorz The Magical Taco and Noob Spriter