Crazy Headcanon Development

I honestly just feel like I don't have enough blog posts. That's the only reason I'm posting this. Anywho...

I've been watching pony on my phone before I go to sleep, and naturally watching pony late at night leads to me creating crazy headcanon. So, to give people fair warning, this post will be about my process of developing my obscure headcanon that no one else agrees with. It will also give you a slight insight to how crazy I am and give you a small (mostly) accurate timeline.

Welp, here goes.

It all started when I set out to make a pony timeline one night. I guess I was bored or something. However, I noticed that in s3 e1, the crystal empire, Celestia talks about how Sombra was banished 1,000 years ago. In the flashback, she and Luna vanquish Sombra. However, in s1e1, we understand that Luna was banished 1,000 years ago. Since obviously Sombra was vanquished before Luna was banished (she's in the flashback helping Celestia), we can reasonably assume that one of these is slightly off; I'm inclined to think it's Sombra who's a bit off 1,000 years, since in the Luna prophecy it states pretty clearly "on the longest day of the thousandth year, the stars will aid in her escape."

However, this raises an interesting fact: that Luna turning into Nightmare Moon (and her subsequent banishment) took place only a very short time after she and Celestia vanquished Sombra.

For a long time I've had the headcanon that Nightmare Moon was sort of a mentality, a consciousness, that invaded Luna's heart because of her jealousy, but was a separate entity from Luna; while her jealousy of Celestia bid it enter, it wasn't actually her acting when she refused to lower the moon. But this timeline revelation made me take this a step further:

What if "Nightmare Moon" is also what causes Sombra to do evil stuff? What if the act of vanquishing Sombra somehow transferred this other consciousness to Luna?

This is also somewhat supported by the fact that Sombra rises again not long after Luna returns from her banishment and overcomes Nightmare Moon, so this could be a case of "Nightmare Moon," having been defeated, returning to it's previous possessor.

Anywho, here's the basic timeline of events I had. Feel free to post stuff to it/discuss/etc.

[Ancient History]
- Starswirl the Bearded
- Starswirl mentors Clover the Clever
- Blizzard; Hearth's Warming Eve; Equestria is founded
- Sometime before this point: Crystal Empire splits into independent state from Equestria [okay, this is headcanon; but certainly Crystal Empire is founded]
... [~ 1,000 years prior to s1e1]
- Sombra seizes control of the Crystal Empire
- [Headcanon] Equestria invades the Crystal Empire, now fully under Sombra's regime
- Sombra vanquished by Luna + Celestia
- Luna turns into Nightmare Moon; is banished by Celestia
... [RECENT]
- Smith family settles Ponyville
- Apploosa settled
- Changeling Assault on Canterlot
- Princess Twilight Coronated

NOTE:
I did consider the possibility that "On the longest day of the thousandth year" was referring to a dating system, so that "the thousandth year" would be something along the lines of the date when Equestria was founded. However, I couldn't seem to make this work, so I'm inclined to think that it's the thousandth year *of Luna's banishment*

Um, yup. I think that's all.