Demon Slayer: Why Do I Have a Parasyte?

(Demon Slayer fanfic + Parasyte) (Nearly invincible + no female lead)

After programmer Lin Che finished watching Demon Slayer: Mugen Train, he was on his way home when a parasite from another world called “Little Lefty” infected his left hand.

At a critical moment, he copied a scene from the movie and tightened a headphone cord around his arm. By a twist of fate, he ended up joining with Little Lefty as a symbiote, and together they transmigrated to the world of Demon Slayer.

Later on, Lin Che realizes: This isn’t how the story is supposed to go!