The Swordsman and the Asura

Susamaru had always been a carefree demon, happily slaying Muzan's enemies with Temari in hand and a smile on her face, thinking nothing of the lives she took. But after a very near brush with death severs her tie to the demon lord, she winds up attached to a certain kind-hearted slayer who just might be able to show her a new path she'd never even considered.