My feeble attempt at offering suggestions for improvement are at following - firs since you have show atmospheric displacement for the hovering or flight I would add more debris and dust to the foreground. The armor is indistinguishable between the thigh, knee, and shin but yet has a metal feel to it - I would work on breaking that up so movement would feel realistic. The wings are well defined but not so well between the outlines which makes me wonder if there should have been a filler in place - just me of course. Outside of that - your choice of composition - pose, colors, etc is outstanding
It is beautiful, just beautiful. Perfectly represents the futuristic world of "Fairy-Zero". A story I wrote long ago and whose protagonists are precisely like those Android has so magnificently illustrated.
Currently I am becoming a Radio-Drama, so that you can reach a wider audience. You can hear it in my SoundCloud:
[These two are "audio test", I release the final in the near future]
The truth is I do not have anything that can "illustrate" the story so as not for commercial use, I was wondering if you let me use it as cover of Fairy-Zero. Of course, the rights of illustration would remain yours, and put a link to your DA. If you can not, nothing happens, but hey, it would be an honor to have this as a cover illustration.