These are really good so far! Napoleon was pretty cute I have to say :3
I have been meaning to check in here for ages but never got around to it, my apologies! I think with regards to your latest Gardevoir piece, the concepts are really good, but I'm going to talk about the base Gardevoir for now. While I can appreciate there is shading there, I feel the piece is very flat, and takes away from the depth and detailing of Gardevoir. A little more dynamic shading wouldn't do any harm, and that goes for most of your pieces I think. You're most of the way there, but your proportionality and anatomical design of the Pokémon just feels a little off to me. For example, the length of Gardevoir's foremost arm is too long. For the angle she appears to be in your picture, her arm is as long as her body.
Reference:
In this picture, Gardevoir's arm is about half the length of the dress-like feature she sports. It is also worth noting that the back piece for the red charm is rounded, and not pointed. And even with the minimal amount of colours used, the anime-style of shading really gives Gardevoir some depth. Of course, with the anime style of shading it's limited, but hopefully you can see what I mean.
Your shadow is good, and with a good light source/shading, you could give this piece a lot of depth and really liven up the picture. Your best piece I can see whilst typing this for shading would be Latios, but even there it could be given a bit more attention.
I really like your drawings thus far. I think for your next piece really try and focus on shading. That is where you need to improve next. Good work so far, and update again soon, so I can see how you improve :D