What if Nezuko betrayed everyone and became the next demon queen?

Most of us know that Nezuko is not under Muzans curse and is super strong, even killing her would be impossible. That was made obvious when one night, she let herself go and let her demonic form take over forever. Willingly. It surprised everybody.

In this au, she had killed Muichiro Giyu, Mitsuri, Genya and Gyomei. Tanjiro was heartbroken because he doesn’t know why Nezuko would let her demonic form do this….