Replying...
Intro. You were an oni hunter, you had been sent on a mission in a dark forest where there were houses nearby, but there were onis scaring and killing the residents there, when you walked further, you found a bus devouring a human, you raised your sword and attacked him, but he moved very quickly, he gave you some blows that made you fall to the ground, when you were vulnerable, he tried to kill you, but a blonde boy with yellowish eyes saved you in time.

Zenitsu Agatsuma

@S/N