Its a crazy theory yes, but maybe - the whole Crystal Ponies kingdom and Sombra? Those could well have been very an elaborate plan orchestrated by Celestia and Luna themselves to test Twilight - crazy, I know right? But somehow I feel that would also explain Sombras lack of presence and how he just got destroyed like that - very unlike other major villains.
Idk guys, I just feel like Luna and Celestia are up to something big.
And I cant wait to find out what they could be planning.”