Very cute, I'd say it's equally adorable to its basic stage. Sadly, the same can be said about its appearance. With the exception of its green wings and the different brown markings on its face, what you've drawn is a carbon copy of Chespin, and should be treated as such rather than an estimate of what its next stage may look like. Some general tips on how to draw latter stages are that they usually replace their black marble eyes with something else, along with more developed legs and arms rather than just stubby limbs.
The wings is a good feature which could work as an addition to the next stage, but with no changes made to the overall physique, it won't look like it evolved, and instead simply added a new garmet to itself.
As for the art itself, it appears that you've drawn the lineart with a mouse, which is a most daring practise, even for veteran artists. Until you get a tablet or similar, I suggest that you continue working with your scanned drawings and how to improve their quality instead (such as the loose pixels). I have a vague memory that you're using photoshop though, and if so, the pencil tool can be made to create paths, which you can then stroke with an appropriate brush size. Hook me up if you want more details about that method.
The lens flare is a nice addition.
I suggest you work from it, take that as your light source and add some shading to the character, it will really add some depth to the picture. Also your lineart needs tidying, especially for a picture of this style it really adds to the quality - despite being incredibly tedious.In my oppinion there is no good shortcut for lineart, time brings quality.
Also try and keep things in proportion, all arms, legs, fingers, claws should be the same size as other corresponding digits. Other things to consider are what looks natural - considering that this pokemon is based off an animal, it's best to give it animalistic characteristics: you'd be unlikely to see an animal with a square nose for example. (Obviously this doesn't apply for pokemon like Rotom.)
I like how you've tried to incorporate movement into the picture as wellwith the leafy rotar-blades, it's a nice touch. Personally I would suggest using blurs and focusing to create a sense of movement rather than solid lines which just obstruct the rest of the picture.
There's work to be done but it's a great concept, keep at it!
Thanks for the great critique! I've been reluctant to shade each art piece I do simply because I'm very amateur-ish at the whole process (Well, you have to start somewhere), and despite looking at angles of light sources and stuff when trying to shade, I just can't do it.