Great Crystal War



"The Great Crystal War, huh? Well, that's when a conflict between Equestria and the Crystal Empire would be waged on each other since Starlight Glimmer made this alternate timeline, and you can see it in a My little Pony: Friendship is Magic season five episode, 'The Cutie Re-Mark - Part 1,' but will that be so similar when the Great P365 War did happen?"

--Su Ji-Hoon, The P365 Returns

The Great Crystal War is a war waged between Equestria and the Crystal Empire in an alternate timeline created by Starlight Glimmer. It is featured in the season five episodeThe Cutie Re-Mark - Part 1 and Enterplay's collectible card game.

In When the Cold Breeze Blows Away, it would be mentioned in during pre-World War III when Equestria and Crystal Empire have their own history.

In post-Last Day of Equestria, the Great P365 War would be happened when Equestria (with support from Gerasecia and the Crystal Empire) and New Group P365 became fight each other.