Fox Fairy Repays Favor

This story combines the core of the traditional "Fox Fairy Repays a Favor", and adds the popular "system", "light novel" style and "urban cultivation/alien" elements of modern online literature, aiming to build a long story with both classical charm and modern excitement. The story is set as follows: the protagonist Lin Shen (male) accidentally rescues a dying nine-tailed fox cub in a modern city, and then travels to a different world where demons are rampant, and obtains the "Fox Fairy Repayment System". But he discovered that the so-called "repaying a favor" was actually a process in which the fox (pseudonym Ali) changed his fate and even sacrificed himself in order to repay the favor.