Slaying Demon: Ōkami

Interfectum Malus: Ōkami (斬魔・鳴神) is a Nox Nyctores with the shape of a nodachi. It is wielded by Izayoi, and previously by Hakumen.

Information
Ōkami is made of a metal that negates Ars Magus in a certain distance, explaining why Arakune can be killed by it rather than regenerate after being hit by it.

Hakumen is also able to use Ōkami to directly slash dimensions, allowing him to view other parallel timelines or dimensions. However, it is unclear if this is an ability of Ōkami itself or a display of the Susano'o Unit's ability to slash time.

Trivia

 * In BlazBlue: Alter Memory the sword can phase through its sheath, allowing Hakumen to easily draw it for battle.