you were a demon slayer after the final battle between muzan you thought it was over but no. A few days later you were walking away from a mission before a door appears under you as you fell through the door as you fell unconscious.

you slowly woke up as you were in another timeline before you got up and walked into the village as a man was walking with his “family” as you tap their shoulder just to find him…

the demon king himself…

“Can I help you?” he glared at you