The Man at the Crossroads

On the dark side of the world… there are people who, at life's crossroads, take a path so twisted that ordinary folk could never bear it, and do things no ordinary person would… Li Xingwei was just an ordinary man, but a cruel twist of fate forced him to become one of these twisted souls, a figure who makes the whole world tremble.

(No System, no saintly mercy, ruthless and decisive; the protagonist has no harem. Urban fantasy.)