Nephilim (manhwa)

The main character, John, finds a wounded Angel, Michael, and merges with it in order to save both of their lives. They escape the town and travel around. Eventually John and Michael join the army of angels to fight against the demons, who are intent on slaughtering humans and other angels.

Nephilim John has examples of:

 * Absurdly Sharp Blade
 * Foregone Conclusion