Due to his half-breed blood, Inuyasha temporarily loses all his demon traits and powers on the night of a new moon, effectively becoming completely human. Early in the series, Inuyasha acquires , a powerful sword made from a fang of his father that can absorb demonic powers and energy. This proves to be useful to keep Inuyasha from falling victim to demonic nature turning him into a berserker. Over the course of the series, Inuyasha develops Tessaiga's signature , and techniques. Eventually, Inuyasha gains a new ability in that Sesshomaru prepared for him as part of their father's design.