InuYasha

Kaijinbo's Evil Sword (2x17)

:

Sesshomaru goes to a swordsmith, Kaijinbo, to get a new sword made from the fangs of the demon that broke Tetsusaiga, Goshinki. But something unexpected happens, and Kaijinbo attacks Inuyasha on the night of the new moon, when Inuyasha reverts to his human form.