User blog comment:Omega natsu2/Chapter 373: Let Live Or Let Die, Predictions./@comment-178.240.51.161-20140223001822/@comment-7418318-20140225095254

Counterquestion: Why did Erza try to preach Kyouka into living for herself instead of following Zeref?

Answer to both questions: It's just an FT thing, particularly for Mirajane.

While Tempesta is not trapped behind iron bars, she could try to free him from his servitude to Zerefn and Kyouka. Tempesta doesn't even know why he does what he does. He just follows orders like a robot, barely knowing what and who he is.