 After Ichigo and his friends break into Hueco Mundo, Aaroniero seeks out Rukia and, in the guise of Kaien Shiba, attempts to use Rukia's guilt at Kaien's death to trick her first into allowing him to kill her.However, when he almost attempts to trick her into killing her friends, Rukia senses something is amiss and engages him.Though eventually unmasked, Aaroniero reveals that he was not merely shapeshifted, but actually in control of Kaien's spirit body.