Holy Night: The Zero is a Manga/Manhwa/Manhua in english language, Manhwa series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Brothers Kang Bau and Joseph were raised together in an ordinary orphanage, but their paths would drastically diverge. Joseph, who became an exorcist priest, descends into darkness and brutally slaughters the orphanage family that raised them, transforming into Lucifer, the great demon. Armed with nothing but his superhuman strength and bare fists, Bau swears vengeance and hunts down Joseph's trail. Yet even Bau's extraordinary abilities pale before Joseph's incomprehensible demonic powers. As threats mount and darkness closes in, can Bau overcome his inner turmoil to stop Lucifer's diabolic scheme and save humanity?