Once upon a time, this was one of my favourite episodes, but as much as I enjoy it, I see it has a lot of problems.
In my first review of "The Crystal Empire", I adored it. The epic scope of the episode wowed me, and I was enamoured with the ambition of it all. Watching it again, I still do adore those elements. The scale borders on the epicness of high fantasy, it's easily one of the most ambitious episodes the show has ever attempted, and it still boasts the most gorgeous visuals of the whole show. It's also heavily flawed. Not enough to keep it from being enjoyable, mind you, but enough to prevent it from being one of the show's best.
The episode starts out with mentions of Twilight having a test, something that would make her "closer to being ready". This idea comes out of nowhere. There was very little mention of Twilight being prepared for something in previous episodes, so this bit of the story is a bit confusing. The episode ends similarly, and said ending appears to place Twilight on a pedestal. At this point in the season, it's not much of a problem, to be fair, but it's not a good direction to be going in.
The main lesson, where Twilight displays an understanding that she must value others over herself, is weak as character development, because by all means she should have already learned this. In fact, Twilight's character trait of taking serious events as a sort of "test" is manufactured for this episode, and is anything but a good addition. Twilight was previously able to take events seriously, but that's suddenly gone here. Not to mention, as a lesson, it's awfully poor. Lessons have been basic before, but rarely have they stooped to the condescending levels of "don't be selfish".
The story itself is a little shaky, with a few notable holes, mainly in regards to Twilight pulling spells out of nowhere. On paper, I'm not even sure how much this plot works, as on paper we're left mainly with Twilight's non-character development and a villain who doesn't do much. But it's the execution that really pulls this episode together. The story is presented on the grandest of scales, packing more intensity than we've ever seen from MLP. This is largely due to the pacing, which draws things out at just the right lengths to create that sense of scale. Meanwhile, there's hints of lore scattered all over the place, broadening the universe in interesting ways.
This episode also shines on an audiovisual level. The camera angles add to the grandiose scale, and show off the absolutely GORGEOUS art direction. This episode remains the prettiest episode in the series, as the crystal architecture boasts some truly wonderful design. The Crystal Empire itself is so beautifully realized that it deserves better plots than what it gets. The sound design also adds to the sense of scale, with pieces that perfectly underscore the moments. The vocal songs are catchy as well, although they feel derivative compared to what's come before.
It's a good but not great episode, one with endless ambition but mixed execution. It tries a lot of things, but many of its ideas aren't very good. A subplot is set up here but isn't actually justified, the attempts at character development fall flat, and the lesson is weak. That said, it's greatly entertaining due to its gorgeous visuals, great music, and sense of scale, and it's a difficult episode to look away from in spite of its flaws.