Air, the purple shading on the skin and shirt looks great, but the colour scheme on the clothing really isn't working that well. The pants look kind of hideous and the greens feel sort of wrong. Not a bad job, but I feel like you can do better.
Kozi, Aside from what's been pointed out, these do look great, but the shading on the lance, near the hilt especially, is fairly off. I don't have any solutions for reference or a specific way to fix it, but that part could be rendered a bit better.
Fowlie, looking good! The angular shaded areas are real rad.
Qyz, tighten up those brushstrokes and utilize them better. You should use a greater variety of brush widths, and work on where the figure meets the ground. It looks like she's floating. The colour scheme is nice though.
Garic, Much better.
Vanilla, the marker looks MUCH better than the digital colour. The shading and highlights on the digital one really don't work terribly well. Given your style though, the more simple and subdued the colouring the better. Watercolours survive the scanning process much better and give you a wider spectrum you can use, and sit better within simple linework. If you do want to continue with digital though, I'd work with desaturated colours and experiment more with organic textures.
The Great Switcheroo
Madd vs. Tam
@ 8:33 PM May 2nd