In Korean, it’s 위장자. In original Chinese, it’s 伪装者 (Weizhuangzhe). I consider this to be one of better ones out there.… The Disguiser 
Before you go on, I warn thee: This is going to be long, very looooong. And this article is FULL of spoilers. You’ve been warned.
Known as Xiao Ao Jiang Hu (Chinese). In Korean, it is called, 소오강호 (So-o-kang-ho), is an ancient Hong Kong novel that was serialized between 1967 to 1969 in newspaper.
In English, it’s known as The Smiling, Proud Wanderer.