Become the Lord of Cthulhu is a Manga/Manhwa/Manhua in english language, Mystery 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

After the death of the male lead Su Qi, he traveled to Los Angeles to become a high school student. Because of inspiration different from ordinary people, I found that there were all kinds of ghosts and gods around me. In order to survive, the male protagonist did not get eaten by ghosts or lost control of his mental breakdown. He embarked on the path of disguising himself as a god, and unfolded the story of exploring the mysterious world of Cthulhu elements.