Her brother is the biggest reason why she doesn't kill humans, and if not for the plot, Tanjiro is a Blood Demon Art away from getting separated from Nezuko. If that had happened, no one could ...

Nezuko, and the gun-toting Genya had a tough time taking this foe down. He was a coward, but spinelessness somehow fueled his power — Hantengu's Blood Demon Art divided him into his primal emotions.

Demon Slayer is a series that places significant emphasis on the turmoil Tanjiro experiences as he looks for a cure for his sister, Nezuko, who was turned into a demon by Muzan Kibutsuji.