He Who Fights with Monsters

Jason Asano was managing an office-supplies store. Now he is somewhere else entirely, with no clothes, no explanation, and a set of abilities that a helpful interface keeps describing in terms like "afflict" and "consume". He would prefer to be a hero. The powers he has been handed are on the other team.

Between the cannibals, the cultists, the wizards and the local aristocracy, the first day alone is a lot. Jason survives on being funnier and more stubborn than the situation warrants, and slowly works out that a system which rates people by number is not the same thing as a world that makes sense.

The first book of the He Who Fights with Monsters series: an isekai LitRPG in which a laid-back Australian keeps refusing to take a very serious world seriously, with a progression system built on cultivation as much as levels, and political intrigue alongside the monster fighting.