It's a nice picture, but a few things ruin it a little bit. I would say that it's evident that the artist was drawing at resolutions beyond own control. One proof of that is Byakuren's leg and foot, that I am guessing couldn't be on screen at the same time while drawing. Ending up highly disproportionate. I am also wondering why some characters have band-aids over their privates, but it looks to be an artist choice based on "body type".
List of debt(ors):
Hakurei Reimu
Kirisame Marisa
Ibuki Suika