Some more feedback and suggestions
"I second the compliments about sticking with the Sugimori style- pretty impressive. That said, I think that she could do give the characters more depth if she used multiple layers of color, ideally different colors that mix and enhance the drawing. For example, Breloom's green can have yellow or peach mixed where the lighter areas are to give a sense of warmth from the sun, and a teal mixed where the shadows are would give more depth and a richer shadow.
Color mixing can get much more complex, with the colors straying significantly from the base color. Obviously, extremes like this don't suit Sugimori's coloring style, but I would recommend playing around with mixing colors for non-Sugimori-style drawings.
In the case of the slug-dragon and dragonite, the cave in teh background could have much more depth if colors besides grey had been used. Indigo or blue-violet would have worked well as they'd also contrast the dragonite's colors and make the lighter purples of the slug-dragon stand out."