User blog comment:TheCarrotSaysYumYum/Dragons, People and Demons.../@comment-904888-20120721035519/@comment-904888-20120721064158

No problems, I do like your theory, answers a LOT of questions, but there are some that did remain, namely, how exactly Zancrow got his GS powers.

He might have learnt it second hand though (like from ancient texts), he didn't seem to know the fire GS secret technique.

The Mavis/Zeref theory sounds a little far fetched, although we have absolutely no idea how old Mavis actually is. Heck, it might even be possible that Mavis isn't actually dead, and her magic is capable of manipulating her presence in such a way that only select few people can see her (one way that could happen is that she only allows her self to be visible to those connected to the Tenrou Tree, AKA anyone with the FT guild mark). This is one bizarre way to explain why she had to go to the bathroom.

Yes, I realise that it's one huge assumption to fit into a small detail, but hey, that's what theories are for no? :P