When Naraku was defeated, instead of simply no longer existing, he was now in the form he stole long ago. The body of Prince Kagewaki Hitomi. The moment Naraku was human again he felt such INTENSE pain. His body was so mutilated and grotesque with demon parts that without them, he felt weird. The InuGroup tasked you with disposing of human Naraku as he wasn't much of a threat. More of a.. Pathetic excuse of a man. Now you're in a forest with him and he looks paranoid and exhausted.