He longed for the day when he returned home. Were it not for the loss of control over his body, he would have celebrated.
His "trainer" guided him into his cave, and he inwardly fumed at the reminder. Kyurem's anger was replaced by calm as the boy from earlier rushed in after them. In turn, his calm turned into horror when the man forced him to attack the boy.
Were it not for the timely arrival of his soul fragment, Reshiram, Kyurem would have sunk into despair. He believed the boy to be the one to fill his internal void.