Let me give my review in just a few lines:
Good start.
Very good middle part.
Poor ending.
Very bad end.
The latter story-line, imho, is seriously flawed. As some reviewers said this manga has a number of loopholes making the latter chapters non-understandable. I don't know if I should recommend this manga. But let me give some notes, read it only as "just another enjoyable manga" without delving too much into the story else you will regret it like me. You've been warned. I repeat THE STORYLINE IS BAD!!