Potentially hot take? Nightmare Star has a better design than Daybreaker
Before we get into my take, for those who don't know, Nightmare Star is an evil Celestia from a world where she rules Equestria in eternal daylight. She first appeared as a card for the Absolute Discord set for the MLP collectable card game. The set was released in 2015. She also has her own poster and she has another card, which is simply just a trading card.
Now as for why I think she has a better design. Daybreaker feels too similar to Nightmare Moon's design, which is no surprise when you invert them both. Nightmare Star also just feels more regal when compared to Daybreaker. She has actual regalia, while Daybreaker just wears a helmet, a chest plate, the orange armor things on her wings, and the shoe things. While she does have a red jewel in her helmet, it just pales in comparison to Nightmare Star to me. Also, she has way too much orange going on. The armor is orange, the splotch where her cutie mark is orange (and it makes it hard to make out her cutie mark, too). And her flaming mane. I'll be real here, it's way too yellow, not enough orange and no red. While Nightmare Star's mane is perfect. It has an even amount of yellow, orange, and even red in it. Not too much of one color. Now, I could go on and on, but this post is already a lengthy read, so that's it.