I've been looking for this doujin for now. It's called Taika no Utage/Feast of Degeneration.
The original header is 退化の宴.
Here's a link to the doujinshi database where I discovered it: http://www.doujinshi.org/book/591736/Taika-no-Utage/
And a Pixiv ones:
http://www.pixiv.net/member_illust.php?mode=medium&illust_id=35180792
I don't think a digital version is available. It was apparently sold at Kemoket 2 in 2013-05-04.
If anyone could find it and scan it. I would be appreciated.
Link inside this site:
https://e621.net/post/show/470784/bakugatou-charizard-comic-dragon-eevee-eeveelution
Updated by DJChris