All right, the excessively long wait is over and we got another two-part premier.
First, we get a full episode of Twilight as an alicorn (Many would put this under the "bad" section but I've always been looking forward to more of our Twilight Princess). MMC only has her an alicorn at the end, and Equestria Girls has her a human for most of it.
Second, it does not entirely retcon the ending of Magical Mystery Cure. The beginning shows Twilight can fly, she's just not very good at it. My guess it, her flight at the end of MMC was her first, and when she says "Everything's gonna be fine", she crashes. It's the kind of thing they'd do, you know? And again, in EG her not being a good flyer combined with her being nervous prevents her from doing so.
There's also Discord being the ally in this episode, I was looking forward to more of him.
To anyone who fears otherwise, Twilight really doesn't want her friends calling her "Princess" all the time.
Despite the disappointments I'll address below, the villain was pretty dark and menacing, and I think we can all agree it was destroyed just like Sombra. Also, some of them were facehuggers. Think if the others hadn't come along they could have attached to Twilight's face, implanted a Chestburster inside her, and the Chestburster would have jumped out of her chest and evolved into a xenomorph. (whatever it would have looked like but such a scene would probably be too dark for this show both with gore and killing Twilight)
Celestia and Luna both survive, Celestia's supposed death was during her battle with Nightmare Moon 1000 years ago.
The animation. Especially during the Nightmare Moon battle.
And finally, flashbacks of Nightmare Moon and Discord's first defeats. Epic battle between Celestia and Nightmare Moon. On that note, it gives us more insight as to Nightmare Moon's character, because we really didn't see much of her in her true form in Friendship is Magic and all she does is bring eternal night and try to stop the Mane 6 from reaching the Elements of Harmony, only trying to kill them once and using scare/block tactics the rest of the time. This flashback shows Nightmare Moon is as dark as Demon Sunset Shimmer because she tries to kill Celestia, saying it's her only royal duty. And she nearly succeeds, too. An epic scene to rival the changeling fight.
There were a few unexpected moments too: Twilight using King Sombra's magic again, Discord randomly taking Celestia's tail off, and those STAIRS (I saw the King Sombra comments coming from a mile away).
Honestly I have only one complaint about the episode: The villain(s). While those black vines were both menacing and dark, and did get destroyed as I was hoping for another villain death, and did reference Alien by some of them being facehuggers, the vines have no real character, no speaking lines, not even a name.
OK, so Discord's the one behind them, planted the seeds before he was turned to stone the first time, but couldn't there have been one seed to grow into a plant monster with more character, some sort of pob controlling the vines? (if you've seen Jumanji) I guess I'm just saying, people complained that King Sombra didn't have many lines (which was only done to make him like Sauron and more mysterious), why would she put a villain like that in after the complaint about Sombra?
I guess they really can't come up with any new villains, can they? So they make it some black vines a la Jumanji (except with facehuggers in place of nightshades and pobs) and have Discord be the one behind it all. I guess my old theory is correct after all, they can't think of any new vil.... Wait, there is the Power Ponies episode. But I guess that's a one-part episode, they can't seem to come up with villains with a story to last two episodes. The only way the vines lasted two was because of the whole "before the Summer Sun Celebration" thing and the flashbacks, as well as the separation thing.
Or, maybe Meghan lost confidence in making new villains after the reception to her previous two. (King Sombra was criticized for lack of screentime and dialog, even though it was done to make him like Sauron; Sunset Shimmer was criticized for being more of a school bully than anything, although many are inclined to take her demon form into account, make one like Chrysalis, Sombra, and Demon Sunset Shimmer, the way Chrysalis was done was perfect and she's number one villain now)
I also wouldn't have minded seeing Chrysalis the one behind them, saying she damaged the Tree of Harmony, and having her destroyed when Twilight returns the Elements. I guess she's dead, or at least Meghan views her so, she's only alive if a.) You take the comics as canon, or b.) You have your own headcanon of what happens after her fall, possibly in a fanfic you've either written or read. If she was going to make an old villain behind it all, she could have made it Chrysalis and given her a final defeat, but instead she made it the villain who's already been reformed. I guess it does add a bit of a "we haven't seen the last of Discord's evil" yet for those who complained that he turned good.
I'll still rank them above Sunset Shimmer though.
Many of you will probably think, will Discord turn evil again now that he no longer has to fear being turned back to stone? Well, there's still his friendship with Fluttershy, which Fluttershy reminded him of when he was probably considering causing chaos again. If Discord was willing to break up this friendship for the sake of causing chaos, he'd have done it in Keep Calm when she refused to use her Element against him, but he couldn't.
One more thing to consider: We saw Discord destroy a vine that had some background ponies trapped. Couldn't Discord have destroyed them all himself? This was more to my "Discord would own the new villains" theory, but apparently he's too busy goofing off (like he was before Twilight ran up to him and noticed the ponies attacked by the vines).
And finally... the mystery of the chest with the key holes. What could be in there?