The protagonist is your usual cliched kid who gets some kind of special power but doesn't know how to work it yet etc. I thought he would be yet another wimpy annoying brat, but thankfully he didn't go in that department far enough and he grew on me. Aside from him, there are TONS of other characters, many who are pretty good, my favourite being The Crow (Shinji), who also has his own OVA, which was great.
There is a lot of good action, cool looking powers and techniques and LOTS of gore. Plus, the anime thrives at displaying it in a brutal manner. The soundtrack was decent too, which helped elevate some key moments.
It's a crime that this anime was only 12 episodes long. They could have made it 24 episodes long and fleshed out the large character cast a lot because it just felt rushed in the later episodes. Also, it is sad to see there is no sequel for it since we don't really get to see a proper end of the story, many of the stuff is just laying around, begging for a sequel. I hate it when this happens.
Even though it doesn't end the story, I thoroughly enjoyed it. Would definitely recommend it to anyone looking for some gory action and interesting setting.