Hello everyone,
Here we are for another review of a rather interesting erogè/anime series that aired some years ago named "Demonbane" based on an original erogè by Nitroplus.
Let's start with a synopsis :
Kuro Daijuuji is a poor detective living in Arkham City. One day, he was requested by Ruri Hado of Hado Financial Group, to search for a magic book. While he initially refused, Ruri offered him a large sum of money upon completion of her request, in which bribed Kuro to accept. As Kuro searches for the book, he unexpectedly runs into Al, a pretty girl that is actually a powerful grimoire. They forge a contract with each other, bestowing Kuro with powerful magic. Soon afterwards, Al also activates Demonbane, a deus machina owned by the Hado Financial Group, to combat the mechanical menace from the Black Lodge. With this, the war between the Hado Financial Group and the Black Lodge begins....
I'll be honest, the first time I watched this series I dropped it after one episode exactly after the scene where the 3D robot comes out, I was rather turned off by the presence of 3D in an anime.
Then after some months I watched it again and well...passed the first initial stage (two, three episodes) you'll end up loving the characters and interactions.
The story by itself isn't the most original, but the continue reference to the Chthulu's mith is quite interesting, and generally the pace is fast enough to give you reasons to go ahead and see what happens.
The whole series revolves around a rather american city of the first half of the 19th century (from the look at least) with the presence of these massive machines to destroy the balance of the world.
To be honest, I found the anime story to be a very quick summary of what happens in the erogè so I'm actually quite interested to read that too.
I have actually the game, just needing some time to play it as my backlog of games to play is getting bigger and bigger everyday 
The main characters are rather few, but their back-story is well developed and you'll find yourself loving almost any of the heroes/heroine.
My favourite character is by far Al Azif (she's a girl, but also a book/grimorie), she's fantastic in her normal form and incredible cute in her chibi form after Kuro calls Demonbane. 
The visual quality, if you can stand 3D in the battles, is wonderful. I especially liked the design of all the girls, it's very good for a 2006 series! The animation is consistent in all the episodes, probably thanks to the 3D in most battle scenes.
The sound quality is high, I especially liked the Rie Kanda's tsundere role as Al Azif especially when in chibi mode!
The opening and ending songs and animation were nothing exceptional or to be talked about, but still the high production values are evident after watching them. (Especially the Opening)
Concluding, , Demonbane has been a fun ride to watch and I'm looking forward to read the original work.
I suggest this series to anyone who likes supernatural/battle stories as this anime is full (with even a little quantity of good comedy here and there), but I do not suggest this as a starting anime as the confusing setting may be a big turn-off.
See you soon,
feal87