[And to her, the returning is important, even if it isn't to him. He doesn't deserve to be taken advantage of, to have his trust and his loyalty used to drive him toward destinations yet unknown. He deserves the chance to make his own decisions about what matters now and what he'll do to protect that. Even having seen so much cruelty in her own world and here, she believes that.]

This stays between the two of us, of course, but... Susato was indeed the culprit behind Rex's death. I know not whether she had an accomplice, but that she killed him is without question.