Kusanagi

Kusanagi is a Noble Art used by Ouma Kurogane.

Description
Like Katharterio Salamandra of Stella, Ouma channels his magic into his Ryuuzme compressing the wind around it, devouring the atmosphere, causing layers and layers to all be stacked together turning it into a powerful sword of storming wind, which expands up to over fifty meters in height. At first, it was able to overpower even Katharterio Salamandra in his initial battle with Stella and it turned the school buildings, practice areas, asphalt into rubble.

Techniques

 * Shin'uchi: This is the Kusanagi in its true form, which Ouma couldn't realize through using his own powers alone, where he continues compressing the enormous tornado several times over using the pseudo magic gathered from his natural element (i.e. wind); this creates a blade of light that is slightly longer than his Ryuuzume. The presence of Shin'uchi was powerful enough to frighten Abraham Carter, a Desperado who described the thin wind blade as having the power to twist the space of the world.
 * Ikki no Kaze: Ouma's strongest Noble Art surpassing Kusanagi, which can be used after Shin'uchi has been activated, where he slashes everything within 500 km of the trajectory where Ryuuzume is swung in a straight line and powerful enough to kill Abraham.

Weakness
Kusanagi's power depletes with each usage, although with the third usage, it was still strong enough to withstand Nene's Black Sword・Yatagarasu. It also requires some time to activate.

Trivia

 * Kusanagi is named after one of the Three Imperial Regalia of Japan, also known as Ame-no-Murakumo-no-Tsurugi and later Kusanagi no Tsurugi, which is explained to be able to manipulate wind.