Cover image of a manga called 風神Rockようこそ妖怪の山へ as seen in this website. The picture (画) is credited to 藤宮裕, who is registered in danbooru's artist database: artist #10474
The artist is therefore finally found. This artist also drew Nitori in the far past (post #287360)
However, I was unable to find the source of this particular image, which is why I added the tag source_request