Demolishing Blade Manifestation: Kusanagi (示現崩剣・クサナギ Jigen Hōken: Kusanagi, localized as Sword of Destruction: Kusanagi) is a Legacy Weapon possessed by the Magical Association. It was wielded by Sechs.
It is a sword-like weapon that requires a level of magical power that few people possess, and generally cannot be used for any extended time. Kusanagi is actually comprised of four paired red and black blades, and only the mastery of gravity-based sorcery allows to utilize it to its fullest.
In addition to being a deadly weapon in its own right, it also has the ability to nullify any kind of Event Interference. In the hands of someone as powerful, it can also manipulate the space/time continuum, allowing small changes to reality to be made.
Its price of use is “shared existence”, which means that the wielder will be the sum of all timelines, for example, if the user sustains a wound from one timeline, it will be present in another.