Like his sister, Amaterasu, Susano was born to rule, but he was tempestuous, with a flaring anger, wicked tongue, and a penchant for destruction. Their father, Izanagi, would have none of it and decreed that Susano live in the Underworld. His mood dark at this news, Susano committed heinous acts of vandalism and murder. Acts that sent Amaterasu into shameful hiding.
Cast low, Susano descended to earth on his way to the Underworld. He carried only his Ten-Span Sword, and regret for his actions. What had his defilements achieved but to envelop the world in darkness? This was his nature, to broil like a storm, to frighten and destroy what stood in his path.
But a storm could also herald life.
At a river side, Susano ventured upon an elderly couple, weeping and cradling their young daughter. Eight children, they'd had once, but now only one remained; seven devoured by the eight-headed serpent. Susano was resolved. To atone for his crimes, to prove his father wrong, to better himself, Susano would slay this beast.
Eight traps he laid, one for each head of the creature, with eight tubs of aromatic saké as bait. Slithering forward, the Orochi spread its gruesome heads to drink from the trapped tubs. Susano cut the rope. Gates dropped. The heads were imprisoned. One by one, he chopped the eight necks, until only the wriggling tail remained. Sweeping his blade split the reptilian hide, leaving notches in his blade but revealing a brilliant sword inside: the Kusanagi-no-Tsurugi.
To his sister, he gave the blade. An act of atonement, but not an apology. His true nature would never change, but his intention could.
Though seen on the battlefield of the Gods, Susano's fight is not truly against those foes, but within himself. He is a raging summer storm, struggling to focus that destructive power at evil, and atoning when the innocent are harmed.