@Eol: I would go with enveloping the gem+wings. While I prefer the image using them as a wall, it doesn't appear as synergistic with the other evolutionary stage you made and aurumoth.
@Umbreons: I would suggest thinning out your middle-stage a bit. It and the first stage appear to have similar body size while Aurumoth looks ridiculously skinny in comparison. The middle-stage dropping a few pounds would give the evolutinary line a bit more progression.
I don't have much to add to the other entries other than they appear to be coming along well, but that isn't really feedback.
I want to say I get more stupid everyday, but it would make me stupid to admit that... Irony...