I think they’ve retained the ability to do svelte designs really well. IMO: Xerneas, Zacian are great. Zamazenta-C is meh but I could see H working in an earlier gen. Yveltal is great (Moltres-G does the same thing but even better). Solgaleo/Lunala are good but don’t really evoke much feeling. Korai and Mirai don’t do much for me at all but I’d probably go Violet just because I’ve usually opted for the darker cover going back to Silver. Lugia/Ho-oh and the Hoenn trio were timeless, straightforward, and really gave clear signal as to what they were about. Dialga and Palkia were a huge shift but did so in a way that fit the transition to DS and made sense with them being literal gods.

What really hurts a lot of them for me has been the consistent weakness of the third legend. Giratina was great and fit with its pair while being different. Necrozma and Kyurem were messes though I get Kyurem’s being damaged. I like Eternatus’ concept but the actual design was meh and Zygarde-50% was great but 100% looks like a transformer. None of those approach Rayquaza.