User blog comment:HalointheSkye/Volume 3 Hiatus - Week 2 - Little Red!/@comment-13499046-20160301223114

Personal theory about the Dragon is not that Ruby's silver eyes inherently froze it, but that "freezing" is something the the Grimm Dragon (being a Grimm of considerable, if inconsistent, size and thus great strength) does as a self defence mechanism when suffering considerable damage. In order to heal, recuperate and go back to terrorizing humans in the future. The Grimm attraction might be part of that.

This goes hand in hand with my Cinder is totally dead can-we-please-be-done-with-her-now-RT-thank-you theory. I just like the idea of her incredulous "What?!" being the last we hear of her.