Nephilim John is a manhwa from the same author of Vagrant Soldier Ares, Ryu Geum Chel. The first couple of chapters are kinda lame, but around chapter 6 it really picks up and I'm really enjoying it at the moment.

Art is wierd as in Ares, but it's much more cleaner here. As with Ares, there's a lot of sword fighting. The difference is that there's the use of superpowers, particularly because of angels and demons.

Anyways, an entertaining read so far, and some good violent action. And it's really getting better after each chapter.

Battle angels, Lucifer, demons, and holy wars: a nephilim by the name of John is abruptly thrown into this world one day when Michael, a battle angel, comes crashing into the room he is in.
http://www.mangaupdates.com/series.html?id=15100

Series is being scanlated by ManWhore, up to chapter 14 at the moment:
http://www.onemanga.com/Nephilim_John/