Board Thread:General Discussion/@comment-25266931-20161228230634/@comment-27082610-20170107043944

But then why is Cinder alive? The Dragon has the excuse of being the biggest and therefore oldest and most powerful Grimm we've ever seen, but Cinder was a relative novice with her Maiden powers. Why didn't it just straight-up kill her?

The reason I don't think it affects the Maidens is because we've only been told of its effects on the Grimm, something Cinder used to steal Amber's powers. Combine that with Salem teaching Cinder to control something when it's fairly obvious Salem is all about Grimm and you've got a fairly convincing case for it being inside Cinder.