Their dresses are based on
saturnspace's arts. I have another sketch of Doc and Derpy, but it is rather elaborate, and I don't think I can make it in a short term, even Saturnspace asked me for that for many times. Well, so I did this one, not so satisfied cause it is not completely finished, but I've got no time, got works to do.
Actually I don't know what is this 'beyond space', I made it up. And the flying creatures, it's some kind of spirit, and yeah I made it up too XD