First of, I will divide this series to three parts. Since this is what i noticed in the changes of the style of the story.
The First part was neat. Well thought off. As said, there will be lots of killing and dying but there will also be saving of course. In this part, we will be shown a small scale conflict between the main characters against this organization of pure malice. This was a good start and made me keep on reading.
The second part is wild, pure chaos. This is like the climax of this second story. Here, I didn't like what happened. In the first part, there was a rule established. We believed the rule. The rule was that characters/heroes come to the last minute to save this and that or perhaps and sudden twist to save this and that. That was on the first. On this second part, this rule was broken. More importantly, it was broken when, to my opinion, mattered most. Lives. Many innocents. Bystanders. Sure, just after that, the mangaka was quick to reason the event, saying it is logical, and nothing is to blame for the heroes/main characters. But he/she did not get that he broke his established rule, that he/she made his/her reader believed. I get the feeling many got angered by this.
The third part which is up to the latest, chapter 152 of the making of this review, was pure perversion. I just skimmed on this part. Rest assured, the hero/main character is not the guilty one but some introduced characters. The story here, on the first and second that was apparent, became so faint now. I believe the mangaka is having a hard time making his chapters interesting and resorting to this unintelligible bits, and not moving on with the story.
Rating the first part, my score is 7/10, the second is 5/10, the third is 4/10
One thing I forgot to tell, there are instances that are also stupid. The characters doing stupid things like guiding possible enemy unknowingly, thus allowing this enemy to take advantage. As vague as I can make it, to show you this so apparent lack of common sense. It was so out there. And don't be lead to this seem like clever solution, although the mangaka throws some scientific terms/reasoning, you would get that the lead to that situation borders to mental. Though it was really interesting at the start. Perhaps the mangaka just got tired of thinking.
