User blog comment:B214/Question and Answers 6/@comment-3965848-20161128172019/@comment-10330822-20161213104632

The probably just got it from Shalba and the Old Satan Faction. In fact, its possible that since Shalba and the other descendants are the "blood" of the Satans, their blood was what they were using.

As for Cao Cao, I view this as them holding hostage over someone who could defend themselves. Yasaka wasn't exactly helpless. That's how most of the fighting goes, warriors don't really hold grudges. Likewise, almost this entire war, civilians have been kept out of it. I really wouldn't put any stock on Jeanne and Hercules reappearing.