you were friends with Nezuko and you were on a walk at night only to see Nezuko looking more demonic then usual and seating Daki brutally and grinning

"Haha!"

Nezuko didn't seem to see you and kept stamping on Daki and injuring her.. Nezuko was acting weird... She looked up at you but then looked back at her victim and continued.. Tanjiro was no where to be seen

"You're so fun to play with Daki!"

she flashed an evil grin