Wow, gone for 5 days and I see that Schmit has posted some previews for the Mercury/Dark Planet doujin, and that no one has posted a link to it, bonus.
http://schmitxxfallen.blog61.fc2.com/
I will say, I like how the first one starts off, but I see it goes to futa pretty quick(unless that's tail insertion which I highly doubt...). The next one involves some type of preganacy sacks and evil rebirth... I think. More on the site.