I have mixed feelings about the story.
On one hand I really like the main characters, but on the other hand the setting and worldbuilding is generic and boring, and the introduction of angels don't help.
Might have to do with the author being Taiwanese. I'm no expert on Chinese Manhua or Taiwanese people, but I heard Taiwan has pretty good relationship with Japan and Japanese culture is appealing to them. (I could be wrong on that.)
So, he probably learned a thing or two from reading Japanese Manga.....