Alright, these are the specific sprites I'd like to critique.
With Boros, there aren't very many technical errors, but one noticeable one is the angle of its right wing is incorrect. It should fold at a sharper downward angle. It's eyes are not done in the Pokémon style either. You also used pretty low saturation colors for basically the whole palette, which isn't common with D/P sprites. Admittedly, its palette is similar to Toxicroak's, though, so it's not a big issue.
Sadly, Huang has the same eye problem Boros has. It's right leg is in the wrong position for a flat surface, which is one of my biggest concerns. I also can't help but notice that the shading and highlights on its feathers make them look rounder the feathers should be.
Like Boros, Lenegana also uses a low saturation palette, though that is not what really bugs me about it. The unnaturality of the flames does. They should be lighter. The outline of any flame in Pokémon never reaches a dark maroon. Also, most dog-like Pokémon have black noses, but if you intended to not give it one, than whatever works best.
Something struck me as wrong about Noves when I first looked at it, and it basically has to do with small flaws in the lineart. For starters, even at the angle Noves has its head turned, its head is too small in proportion to its body. Its legs, especially its front ones, are also longer than the typical horses, but that may have been part of your design.
In general, you have excellent lineart, but some of your palette choices I personally don't believe are consistent with traditional Pokémon palettes.