If you want to learn the techniques of an unreliable narrator in building a dark comedy fantasy story, I recommend the following fiction: (1) Fake Saint of The Year; (2) To Be A Power in the Shadow; (3) Overlord.
I think it's The Eminence in Shadow for LN (that was it's WN name, I think) I've read the second and third one. (And both of them are killing me with the wait for their next volume) Fake Saint of the year? I'll check it out