The sprite is awesome, and I really like how you made the sprite with animations in mind. In the end it will look awesome. Add some wood texture to it and it will go from awesome to super-awesome! As it is, the arm-cannon seems fake, like it was also made of plastic.
Also, the sniny sprite being mechanic... I think you should take that idea and run with it. It sorta makes a contrast between the normal sprite being wooden and natural, while the alternate version is more mechanic and techy. And considering a lot of people hack their sprites with Pokesav, the shiny sprite would be a shout-out to the hackers.
But that's just me. Whatever you do, Pyroak will be great. Don't feel obligated to listen to me, it's just my opinion. I'd contribute myself, but I suck at spriting. So when I get the chance, I'll work on recolors. Someone give me a Dyclohm sprite with the heads sticking out of the cloud as opposed to tucked in, and I'll make a shiny recolor. I already made shiny Monohm, so it'll complete the trilogy :D I'll also do Colosshale and maybe Privatyke. (if someone else's shinies aren't already official)
One last nitpick. About Kitsnoh. His 5th gen sprite. The tail makes him look at first glance like its floating or gliding or something to do with air and flight. It's just the way it's angled in a baloon shape. It takes me a couple seconds of closer examination to recognize that it isn't the case. Seeing past the tail, it's a great sprite, but I don't want to have to see past the tail. Again, that's just my opinion.