Matou Kitan Zankan is based on manga by Ruuen Rouga, who also did the original work for Trouble Evocation. It is a two episode OVA at 28 minutes each. Released from 1996 to 1997.
At the time of this post, I made several attempts to watch this, but apparently due to its age I couldn’t access the hanime to watch. Also, there is another that goes by the same name but the title includes Jinma Konton Hen. Or that’s the name of the manga. So that led to some further confusion. The most I could gather is that it starts in a private detective’s office. Where someone walks in, a really good looking woman, but it turns out she’s a succubus. And I guess the detective escapes just in time. There is apparently a lot of demon and monster sex scenes. So I anticipate tentacle porn here.
I did go on a review to at least get some idea of some aspects of the hanime. Turns out sort of gives off Pokemon/YuGiOh vibes with the way he uses different girls inside his crystal to fight demons. Well isn’t that fucking interesting. So that leads to the question Can familiars evolve? And are there legendary familiars?
This is all I got for Matou Kitan Zankan until I can actually find it. It’s probably hidden on the 88th page of google. I’ll update this post with something when I have it.