His True Purpose is the 280th chapter of the InuYashamanga.
Synopsis
Inuyasha saves Kōga from a crumbling Mount Hakurei.
Naraku reveals his true intentions to Kikyō and then attacks her.
Summary
Inuyasha goes to save Kōga, who is falling down the shaft of the mountain, telling Kagome and the others to escape while they still can. When he gets a hold of the wolf, he notices Naraku was trying to dissolve him jewel shards and all. When Kōga wakes up, he asks where Naraku is, and Inuyasha says they can talk about it later once they escape the crumbling mountain. The two of them are able to get out of Mt. Hakurei before it collapses completely, but when they almost get crushed by falling rock, Kōga uses his speed to push them forward. He goes to see Kagome, acting like he got out all by himself with no assistance from Inuyasha, but just then Inuyasha appears and beats the wolf over the head for his lies. Kagome says Kōga should thank Inuyasha, but the half-demon says he doesn't want everyone to get the wrong idea; The only reason he saved the wolf was so Naraku wouldn't get his sacred jewel shards. Kōga says if that's the case he doesn't need to thank him. The two of them then bicker over Kagome (as usual.)
Naraku confronts Kikyō. He tells her that he has a new body, but Kikyō is unimpressed. She says that Naraku wouldn't erect a purifying barrier and hide deep within the mountain for such a simple reason. She asks him what his true purpose was at Mount Hakurei, also asking what it was that Kagura fled with from the mountain. Naraku says there was simply one thing he needed to accomplish at Mount Hakurei.
Naraku slashes at Kikyō, snapping her bow into pieces and cutting her across the chest with his sharp talons. Inuyasha suddenly gets a bad feeling.
