Seshomaru challanges Inuyasha in order to see if Inuyasha is worth having Tetsusaiga. He uses a fragment of Kanna's mirror to create a replica of the sword from Tenseiga. The fight between the two takes place in an uncertain place where Naraku sends them for the first part.The second part of the battle is taken inside a Meidou Sangetsuha created by Seshomaru and is rather between Inuyasha+Seshomaru against the sword that is now manipulated by Naraku. Inside the meidou Inuyasha mannages to defeat the meidou by using the dragon scaled Tetsuaiga to cut his own yuketsu. That convinces Seshomaru that he is the true heir of the sword and when Naraku attacks Inuyasha he decides to help him, but not directly. In the end Tetsuaiga gets the Meidou ability from Tenseiga and that is how Inuyasha and Seshomaru manage to exit the meidou. The episode ends with Seshomaru's group and Inuyasha's parting.
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