Beware of Obsession is a Manga/Manhwa/Manhua in english language, Action 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 gigantic tree plunged the city of into the midst of chaos, causing people to lose their sanity, and some even turned into demons. Ten years later, the protagonist, on his way home from work, coincidentally saved a mysterious young girl but lost his own life in the process. Upon awakening once more, he discovered that the girl’s soul had inexplicably merged with his own body. Not only that, he found himself able to wield the girl’s demonic powers. In order to unravel the mystery of the girl’s origins, Lin Sheng qi embarked on the path of demon hunting…