Spoiler Warning: Some spoilers from Avengers : Endgame in this story.

With a snap from an all-powerful gauntlet, Tirek turned half of Equestria to dust with the six Harmonic Stones.

The survivors are left distraught by Tirek's actions and now have two goals in mind:

1.) To return those who were dusted by Tirek's snap
and
2.) To get their revenge on Tirek for his unconscionable act

With only three of the Mane Six surviving the snap (Rarity, Pinkie Pie, and Rainbow Dash) - these goals will be much harder to achieve than ever before.

NOTE: Except for minor appearances, no one from the MCU is showing up. That would be too easy - wouldn't it? Except for a little bit in Chapter 1 - I'm not planning on a full crossover.