so we have this post #247620 here
If you have watched the Mondaiji TVA carefully enough you will know that the endcard image of Episode 09 is drawn by しらび and not this random "fa-chan" guy.

To make sure I checked しらび's blog and I found his claim here: http://shirabi213.blog111.fc2.com/blog-entry-279.html

However currently this replica enjoys the highest resolution so I think ppl may need it...

Here is a capture of Mondaiji Ep.09: http://livedoor.blogimg.jp/karekimo/imgs/7/6/7693345a.jpg
You can see little differences here and there (mainly coloring), but these doesn't make this work someone else's in my opinion.

So what do you guys think?

Faa-chan is the pixiv user who vectored the image. Generally though we credit the original illustrator and not the vectorer.

You're welcome to change the tag if you want. Next time you should put such messages as a comment under the relating post btw.