Spoilers to anyone who hasn't read the synopsis or seen trailers
What we know is:
- Celestia and Luna are retiring and making the Mane 6 rulers of Equestria in their place
- Grogar is assembling a team of villains to take over Equestria
- Sombra takes over Equestria himself
- The Mane 6 have the Elements for one scene, which is obviously BEFORE facing Sombra coz they don't have the Elements when they react to him kidnapping Flurry Heart, and are obviously on their way to retrieve the Elements again when he destroys the Tree. But the Mane 6 are still able to power up and defeat Sombra, releasing Ponyville from his control.
Here's how I think it'll go down:
Grogar assembles his team of villains, finding Chrysalis, breaking Tirek and Cozy Glow out of Tartarus, and reviving Sombra with a necromantic ritual. He plans to conquer Equestria and sends Tirek and Cozy Glow as decoys, with Cozy as the brains and Tirek as the brawn. The Mane 6 take the Elements and stop their threats, turning Tirek and Cozy Glow to crystal. Celestia and Luna recognize the Mane 6 rising to the occasion and saving Equestria again and announce that they will retire.
Without Tirek and his magic-stealing, Sombra makes his move and betrays Grogar, either turning him to crystal or letting him escape. He hides the Crystal Heart again and kidnaps Flurry Heart, and when the Mane 6 race to get the Elements again, Sombra destroys the Tree, having been informed of its location by Chrysalis, whom he keeps as either his servant or his queen.
Part 2: Sombra takes over Equestria, brainwashing the Crystal Empire and Ponyville. Celestia and Luna fight him but are defeated. Discord also comes in, but is also unable to defeat him. Probably all three are brainwashed as well.
The Mane 6 face Sombra on their own, and eventually discover the power within them, and unleash a wave of magic that I'm HOPING destroys Sombra (again) but will probably just turn him to stone (coz I want him to die again and the show has barely satisfied me in any other way lately so I have little faith in it to start now), and Chrysalis will escape the blast and fly away, never to be seen again, coz the writers are dead set against giving her story closure.
And if Grogar escapes, then the finale will probably have him revive and merge with the Nightmare symbiote to fight the ponies himself.
For the record: I've waited 7 years for a conclusion to the whole Chrysalis thing, and Sombra was one of the other five I discovered the same year even though I only had to wait months for him. (the other four are from X-Men and Marvel Cinematic Universe) And I've had to endure two months of the worst winter I've ever known, and will have to put up with four more days of hell right before the premier begins. So, you'll understand if I'm making a big deal about this, and it really means a lot to me that I get my satisfaction with Chrysalis and Sombra at long last. I really need this to be worth the wait and everything I had to go through in the middle of it. The winter, losing several friends in the fandom, getting into heated arguments with people here, some of which tried to make me more depressed, the season losing its charm, etc.
But, how do you think it will go down?