Demon Slayer : The Silent Journey - Chapter 70: Karma

This story is about a rookie researcher, who was forcefully dragged away from his restful life, compelled into facing various killers and zombies, always having to risk his life at the brink of death, and finally becoming an advanced researcher that is acclaimed by all. And throughout his adventure, he met an alluring(?) killing machine, who he started to have fantasies on after they had an accidental kiss…

Xiao Yan: Did I fall for him? But he’s a man!

Maya: Who knows…. maybe it’s the other way round?

- Description from Novelupdates

It was only after Su Yayan's death that she realized that she was a malicious cannon fodder female character who became a scapegoat in a Mary Sue story.

Thousands of years ago, the great abilities of the three teachings of Buddhism, Daoism, and Demonism decided on a place for becoming immortal. Three thousand years ago, a Taoist was close to becoming immortal. Three hundred years ago, the Daqian Dynasty was established, and chaos is expected in another three hundred years. In this era, the path to immortality opens; a celestial swordsman freezes fourteen states with one sword, a heavenly Daoist maiden seeks eternal life, a naturally born Holy Son claims to be invincible, and a Buddhist Holy Monk saves all sentient beings.Gu Wen lives as a beggar, enters a household as a servant, witnessing the disordered world, drifting aimlessly.In a world filled with divine beings, he alone is a mortal.However, a lowly origin is not a disgrace; striving through the grand path, even as a common man and mundane son, he can still be the foremost in the world.“Mortal Gu Wen, my Dao is euqaling the heavens!”