Leylin_Farlier AI cheat is neither unique nor charming. it is a crap mechanic that harmed the story a lot.
The charm and uniqueness of WMW is that the MC is evil without being lolrandumb, without doing evil actions that self harm because "must do evil", without hypocritically claiming to be a saint, without breaking character every time a pretty woman comes by and he feels like white knighting her. MC is actually working for benefits, doing bad things when it benefits him and only when it benefits him, and sometimes even doing "nice" things that benefit him too. The only other story I have ever seen with an MC of this high caliber is Reverend Insanity. Every other so called "evil MC" is a random idiot who self harms for evil and white knights pretty girls, doing random things, or being a hypocrite, pathetic.
Moreover, WMW is quite amazing in that it is not an idiot world where every single person in the world is a moron (necessary for the plot to exist). I am reminded when some young master saw his fiance talking to leylin he got upset... then an elder came by and forced the young master to apologize because "making enemies with random people is stupid". This right there is amazing, and makes MCs actual opponents actually dangerous instead of easily outwitted dunces