The Duality Blade or Sword of Pacts is the sword around which the story of The Legend of Zelda: The Sword of Pacts revolves. It is seen as the only means of salvation for Hyrule from the inevitable evil that will purge the land. The sword has the ability to separate light from dark and give those qualities an embodyment, wether it's the sword itself or the person weilding it. The blade symbolizes the unity of light and shadow, as long before the people feared the darkness as well as they feared the Sheikah for their mysterious ways, but, the Royal Family, being short on soldiers since the Great War forged a pact with the Shadow Folk, to include them in their society and not ever harming their people if their people in return would choose one of their tribe to become a Guardian for the Royal Family for each generation. Therefore the sword itself is a testament that in the absence of light, which is only when the darkness appears, that very same Darkness will not harm, but protect Hyrule and it's people, and will again hide in the shroud of light until needed again. Even after being given the freedom of being part of normal society, the Sheikah still stayed secretive and distant from the people of Hyrule like the Zora people, so, there was never a complete trust between the two races.