Heaven Official's Blessing: Tian Guan Ci Fu, Volume 1 of 8 (by Mo Xiang Tong Xiu)

Eight hundred years after his mortal life, Xie Lian has ascended to godhood for the third time, angering most of the gods in the process. To repay his debts, he is sent to the Mortal Realm to hunt down violent ghosts and troublemaking spirits who prey on the living. Along his travels, he meets the fascinating and brilliant San Lang, a young man with whom he feels an instant connection. Yet San Lang is clearly more than he appears... What mysteries lie behind that carefree smile?