From Yen Press:

Rebellious Chiwoo is the town outcast. Without his parents to raise him, he finds this world a difficult place to fit in. If only his mysterious father would just show himself! What secret could drive them apart? When his father suddenly reappears, Chiwoo learns that his father is a Mangnani, a mysterious executioner who carries out God’s judgment. Only his father’s dance prior to the beheading of a sinner determines the fate of one’s afterlife — either forgiveness from God or eternal damnation. Now on the run from an Emperor determined to obliterate all Mangnanies and their heirs, Chiwoo must fight to fulfill his destiny!

From Easy Going Scans:

Kael (aka Ryu Shiho) was a menace in his angelic form, harassing other angels whenever he got the chance to. Therefore, the heavenly fathers decided to expel him to the human world, hoping that his behaviour would improve. But... They guessed wrong. His attitude didn't get any better at all, and to top it off, humans now call him "Lucifer" because of his evil deeds and his scary eyes. If he ever wants to see the doors of heaven open up to him again, he has to perform a hundred good deeds… Will this task prove to be impossible?