Prologue

Y/N L/N was a demon slayer, trained by one of the greatest or the greatest slayer of them all, Yoriichi Tsugikuni.

Although his journey did not last long as a slayer it was still quite infamous as he created the third strongest breathing form, Breath of Venom.

The young man had fought his way through herds of demons with and without his sensei, but this specific one was the last that he would ever face.

He would later he asked by a man these simple words, "Would you like to become a demon?"