Movie 3: Swords of an Honorable Ruler

Inuyasha and Sesshomaru's father actually had three swords, known as the Swords of World Conquest. Tetsusaiga is the Sword of Earth and can kill one hundred demons in a single blow. Tenseiga  is the Sword of Heaven and can save one hundred humans in one swing.  Sou'unga is the sword that dominates this story and puts Inuyasha, his friends and even the entire world,  in peril.   Can Inuyasha and Sesshomaru team up, for once, and defeat this new nemesis?