Episode 176

Sesshomaru in the Underworld is the 9the episode of InuYasha: The Final Act.

Plot
Without his jewel shards, Koga takes his companions and retires from the fight with Naraku, leaving desire for revenge to Inuyasha and his group. Meanwhile, Sesshomaru visits his mother to ask how he can make his Meido Zangetsuha stronger. She summons a Hell Hound for him to battle, which takes Rin and Kohaku into the void of the netherworld. He follows and defeats the beast and rescues them. Though Kohaku is able to move within the void, Rin is not. The darkness of the Abyssal Void envelopes her and Sesshomaru confronts a guardian of the dead. Rin is dead, and Sesshomaru is disturbed to realize That Tensaiga can not revive her again. Sesshomaru's mother seems to sense her son's distress, and uses The Meido Seki to revive Rin and let her live.