Sauce: https://twitter.com/MLP_CCG/status/626503756004368384

Presented with little comment. This is a poster from the official MLP trading card game twitter. Is this a sign for things to come? Has Trollestia decided to play her biggest prank yet for the "lulz"? Will the lunar republic rise? Are alicorns intrinsically prone to dark deviances? Extrapolating this pattern; is Cadance secretly an evil mastermind? Should I start the groups "Alicorn Tyrant"and/or "Tyrantlestia"? Will I ever get off my lazy ass and post the next Tyrant Sparkle image compilation? Do you like mmmmmmmmmm- BANANAS?

To answer your questions.
1. Yes.
2. Yes.
3. Hells yes.
4. One can only hope so. Being immortal/ageless and just short of deific tends to lead to explorations to cope with boredom I would imagine.
5. Yes though not so secretly. She openly brainwashes ponies after all.
6. Up to you. If you make a Tyrantlestia though expect the usual rants and anger from the Celestia defense squad that you can find.
7. If you do I'll give you a cookie.
8. No, I don't like bananas. I prefer oranges or apples.

Also, as a side note, is she a tricorn in this? She has the bicorns horns on her head and a unicorn horn. If she has bicorn aspects now, Cadence needs to keep Shining Armor away from her... assuming he and Chrysalis aren't seeing each other on the side.

Think this might have something to do with a Luna episode. Something where the reverse of what happened a 1000 years ago. I can't remember where I saw that leak.

We all knew it was inevitable, from the earliest fanfics.

4588649
Hm.. I dunno about that timing. If you notice the Elements are there on her throne and have the appearance they took on after joining with the Mane 6. Only the Element of Magic always looked like that while the others were rather ordinary looking gems in the past.

I don't think it is. Everyone thought it was from the Luna episode, but that didn't happen. And, based on the episode titles we have, there doesn't seem to be another place it could fit. I think it was just the card game doing their own thing with some photoshopped vectors.

If it is from the show, it's either an imagine spot, Celestia dressing up for Nightmare Night, or from the season finale.

4591042
Personally, I'm hoping for it to be a scene grab from the work on the My Little Pony movie that won't be out for quite awhile yet.