Thrond

And it looks like Flurry Heart didn't get much to do, either. For better or worse, the lack of expansion on the alicorns really sours my opinion of the show.

Flurry Heart was the centrepiece of one of the season 7 episodes. I'm not sure there was much to do with her given that she's a baby. As someone who quite likes what has been done with Celestia and Luna, I am disappointed that Cadance never got the same treatment. 

I meant expanding on the lore of alicorns. They're said or at least implied to be something special and important, but they're ultimately just there. I can't even say whether becoming an alicorn did anything for Twilight, so the fact that these alicorns exist feels pointless. Thus, I don't agree that the show handled Celestia and Luna well, and I personally hated "Between Dark and Dawn". Were the sisters major characters in "The Summer Sun Setback"?

Even though Cadance didn't get quite so much attention from the show, that might have been a blessing in disguise for me.