I guess I'm late to the party, since I just got a magazine with chapter 1 in it now.
It blew me away.
I have to admit I prefer this manga-ka's style to Oda's (both in Hikaru no Go and Death Note)– everything feels more accurately drawn, less cartoony and more "drama via storyboards".
But I have to wonder... does it run out of gas very quickly? The premise seems almost too simple, as it's laid out by the end of chapter 1. All he needs is forty seconds lead time on any potential threat and they're down for the count. It's pretty interesting how he quickly buries the hypocricy of being a mass murderer who kills bad people-- does the theme come back to haunt him later?
The "when you die, you don't go to heaven or hell"-- I'll assume that's the saving for the ending, like what One Piece is, but let me hypothesize, he becomes a Shinagami too.
Have you hugged your Shinagami today?