>Total solar eclipse
Nightmare Moon blotting out the sun was a reference to a total solar eclipse. Faust was drawing on the ancient superstition that solar eclipses were a battle between the gods.
A solar eclipse in Equestria means Nightmare Moon has returned.
>>30776819
Twilight, Twilight, calm down. You're being autistic.
>>30776819
There's no god today.
Just me.
I'd be her loyal zealot.