How to Use an Angel is a Manga/Manhwa/Manhua in english language, Comedy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

A bunch of thugs holding a demonic invocation have kidnapped Kiom to use as their sacrificial offering. Just as she’s about to be attacked, though, the wall before her crumbles, giving way to a tall, glowing figure. The newcomer is more handsome than anyone could dream of, so pretty-faced that he seems angelic, in fact. Kiom is relieved to be rescued, but the guy seems to have mistaken her for someone else. He calls her by a strange name, and pulls out a…sword?! Will Kiom get out of this alive?