"I think you should keep it with you. Whenever I get too far away from the cross I always end up somewhere near it somehow. I want you to keep it so that I can never be too far away from you." Cain spoke his heart, hoping Kiriko would accept his offer. Cain wanted to protect Kiriko as long as he was able to. If that meant that he would be bound to the cross then sob be it. That was how much he cared for her.