The Niten Ichi Ryuu Gorin no Taisei (二天一流五輪の体勢, "Two Heaven's as One - Flow of the Five Rings") is a koryu (古流, lit. "old school") of the Land of Demons, transformed into a religious movement following the "Demon's Era". Originally a deadly martial art, its practitioners became infamous as Demon Slayers and capable of banishing fiends and other monsters back to the abyss. Eventually as peace settled over the region, they turned to philosophy and spirituality to placate their inner demons and in doing so became known as the Bushido Sect (武士道宗) today.