It felt like all through the episode I kept having to ask why something didn't make sense. Why was Angel such a pushover? Why didn't Fluttershy fly when there was ice? Why didn't Discord just leave? There were a bunch of inconsistencies and plotholes that kept the episode from shining. It also felt like it should have been a two-parter, as converting the evil that wrapped up season one (over multiple episodes) shouldn't have been a feat accomplishable in one episode. I still felt like Discord was playing them, though that's not how the episode made it seem by the end.
This episode was obviously providing the set up for some plot down the line - and it was sloppily done. The best part of this episode was seeing how far Fluttershy has come confidence-wise since the beginning of the series.