This is a thread in which we will plan theories and hype them up before they appear. Feel free to use it if you wish.

•What exactly is Discord: Explaining the Draconequus.
•Spike's Biology and what will happen to him in the future.
•Could Molestia/Gamer Luna exist in the canon universe?
•Alligators/Crocodiles and philosophy.
•Origins of Equestria and Magic.

More will be added to this list soon. I may or may not do each theory in the order in which I have them here.

4638409 Wait didn't I explain three possible origins...

Anyway

The Crystal Heart, origins

4638425 The Crystal Heart already has an origin of sorts: it was mined out of Crystalline Mountain. (Journal Of The Two Sisters, pg.96) Though alternate explanations could be fun.

I know there is no definite answer to this but... maybe a Discussion for the mystery of Equis' Sun and Moon could be interesting...