I’m Having Fun In The World of Mysteries is a Manga/Manhwa/Manhua in english language, Manhua 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 mysterious power revived and spread throughout the world, making the world a strange place. Everyone was panicked and frightened, but Jiang Che, a traverser, was not frightened by it at all, because he could see a strange reminder, namely “System”. After completing the Mystery Challenge again and again, He Suddenly founds that he had become a Mystery Master!