Try blending the colors as suggested before. Other than that, use symetrical body parts, like both Zapdos wings or both Flygon wings, but not one of each. It kinda looks like an experiment of Frankenstein
still, definetly not bad for a first try (i'm one to talk...i've never tried lol)
I wish you had a slight change in the green, like maybe a neon green like the shadow of Zapdos' stomach had. Instead of solid, make a value change in the greens.
Flygon and Zapdos could use shading on the body but otherwise good (I didn't shade the legs on my first sprite so don't feel bad)
The three pixies and Magnaton I don't have any comments on.
Gengar and Gallade look odd but you are improving fast.
I can tell you are going to get good with a bit more practice. Mabye yo ucan open your own sprite shop if you are ready.
I like it, although, overall, you just need to make them actually look fused. This looks like a demented Frankenstein, although very good for your first attempts!