HOLY MOTHER OF GOD!!!
Just when I'm starting to move away from manga to manhwa, this one held me back.
The author is a genius. He knows what the readers want. And his art style is amazing. AMAZING.
The story is just as awesome, I don't think I've ever managed to predict any event in this manga correctly. The unpredictability is VERY strong with this one.
You may be annoyed at certain characters at times, but believe me, they get better!
I think I'm addicted. I even read the Japanese version just to be sure I'm not missing anything, despite my almost-non-existent Japanese.
Go ahead and read this, it's totally worth your time, even if you're running for president of the USA.
Edit: as of April 6th, 2018: The first arc is still 10/10, then it's a downhill from there.