Okay, so I said I'd leave comments in a specific style just a couple minutes before this one, but I found someone's blog where they tracked down Maboroshi Chouji's doujins (link: http://egduj.web.fc2.com/douzin/douzin0401.htm) and found this cover page as the first doujin on the webpage.

From the blog owner's description, this is an original work by Maboroshi where he just draws various monster personifications (which is why it says "She" Monsters right below the main title). They released it on 15 August 1999, which would be the last day of Comiket 56.