@AshAndrewFlame no it doesn't come with the sheath. For the Kusanagi:
It is said that the sword possesses the ability to control the wind and flames. This allows its wielder to manipulate these elements with remarkable skill.
Some tales speak of the sword’s ability to grant invincibility to its bearer or bring forth storms and lightning when unsheathed. These mythical attributes have further heightened the mystique surrounding Kusanagi-no Tsurugi.
So according to legend, people who had this sword were said to have been able to control the weather … which is so cool.
So divine elements and storm (or monstrous elements since the sword comes from Orochi), Invincibility, and insane level of cutting power