CONTAINS SPOILERS

I forgot most of the details as I was reading it as it wasn't very memorable, so here's a quick review of what I do remember.

Story: 5
The plot is fairly interesting and not very complicated, which is fitting for just 12 chapters, but I still had some problems following along. There are some things that don't get explained and some things that don't make sense. We aren't told where the demons came from or how a severed demon arm can be wielded by anyone. It was never explained what exactly the US military was trying to accomplish with its bizarre actions.
The ending felt unsatisfying, like it wasn't resolved properly. It doesn't help that not only did Takeru not die as she was supposed to after the witchblade was severed, she's even starting to recover.

Art: 9
The art is quite good and is mostly consistent from frame to frame and chapter to chapter. Good anatomy and character design, rich colors, and good action poses. The facial expressions and panel layouts leave something to be desired, but the art is this manga's strong suit. Some of the panels could even be turned into posters.

Characters: 5
The characters were mostly average, with some being more interesting and enjoyable than others. Some nitpicks I have are: Kou, the sword guy, is somewhat shallow, and strangely dumb in some cases. In several situations he displays bizarrely poor understanding of the effect the witchblade has on its bearer, despite spending so much time around her. Some other characters are like this as well, but we don't see them display that as much so it's easier to ignore.

That military guy is either delusional or straight up insane. He goes from saying Takeru fighting the US navy is impressive to saying it’s impossible that she’s actually winning, despite calling her a superweapon a short while earlier. That instant change in reaction doesn't make any sense.

The demons were repeatedly shown to be needlessly, maliciously brutal and cruel to various innocent humans, and yet the two most important demons tried to justify it by saying that something similar had been done to them by military researchers. Not only are they overreaching, they're being massive hypocrites, which makes the author's attempts to turn them into sympathetic villains laughable. Them being shown caring about each other and hugging before they died does not erase their extreme cruelty towards everyone else.

Enjoyment: 3
You may get more enjoyment out of this than me. I didn't realize that detailed blood and gore were going to be intermingled with ecchi shots right next to each other, which ruins the effect of both of them in my opinion. I somewhat enjoyed the plot and character interactions, but the gore definitely brought this down a few points for me.

Overall: 5
This was a decently enjoyable read, but not to my tastes. I wouldn't read this again, but I would be interested in seeing what happens after or getting some much-needed backstory.