User blog comment:Omega natsu2/Chapter 352: The Flame's Voice, Predictions./@comment-7418318-20130915175653


 * The village and the giants being affected was just collateral damage with the real purpose of the freezing spell being to seal the Underworld off.
 * The frightening "something" that Wendy feels approaching are Tartaros Mages who, now that Gray so conveniently got rid of the magical ice barrier, can come out of the Underworld again.

And while I'm at it, I might as well repeat a theory that has been stated in review blog comments several times now:
 * The source of the Eternal Flame is the Dragon Atlas Flame.