And it should be noted that the King of Hell from the Chinese is influence from Buddha and Hindu Yama(King of Hell) which originates from India folklore. It is said in wiki that Chinese has no thought about Death God until Buddha spreads in China and then it become a China folklore(The King of Hell by then is also already different from the original Indian Legend or the Buddha King of Hell). Other than the information about the Chinese King of Hell, it is also noted that he has a death book that records the lifeline of everyone which is one of the influence on the Japanese Shinigami pop culture today. 
 From the Chinese wiki: http://zh.wikipedia.org/wiki/阎罗王