Board Thread:Speculation House/@comment-6490434-20130410061505/@comment-4010415-20150407001424

98.71.44.6 wrote: This is a hypothesis, but I think that the moon is holding the souls of the Grimm. The Grimm don't have souls, though.

And I'm not sure if you know or not, but the moon is not breaking and reforming. It's always the same amount broken, just rotating so we see the broken half more or the whole half more.