That's some heavy stuff right there.

Well, the writers decided to go into that direction anyway, so… :\

However, this raises rather interesting question: If princesses can extend their powers to the metaphorical degree (At night, ponies usually sleep and dream, so princess of the night/moon has rule over dream realm to some extent), what can princess Celestia do?

Like, at day, ponies usually work in the fields, so princess of the day/sun can revitalize crops? Or, ponies usually have parties, (not all the time, but bear with me here) so princess of the day/sun can make something more lively?

I don't know. I'm just spit-balling ideas to be honest :\