Yeah, even after waiting a few months to form an opinion on them, I'm not a huge fan of either of these. In fact, they're probably my least favorites of the overall pretty good batch of new Pokémon we've seen so far, and probably my least favorites of all of the mascot legends we've seen so far. The two are both very overdesigned and I think that might stem from the fact that, in my opinion, they are both a complete mess of colors. They're both all of blue, red, yellow, and white, and Zacian's shades of those colors are all desaturated while Zamazenta's are all a bit more saturated. They're all used somewhat evenly on Zacian, and Zamazenta doesn't really use white and maaaaybe blue as much, but that's about it. The distribution of the colors is really what makes this so bad for me, on something like Ho-Oh the red and white are clearly the main colors while the green and gold are just highlights, on top of the simplistic design. There's a lot more contrast in Ho-Oh, as opposed to there being very little here. I will say that I like Zamazenta more though because the shield blends in much more naturally than the sword does for Zacian. They do seem fun to think about competitively, though. Pokémon Showdown is going to continue supporting all Pokémon for their formats, so this would be assuming that. I imagine they'll both be Steel/Fighting, and although we don't know for sure yet, it's fun to speculate so I'll just assume that for now. I can imagine Zacian would be a wallbreaker like most other Ubers, while Zamazenta would be a slower and more defensive Pokémon. So we'd have a Steel-type wallbreaker, and we'd have a Steel-type wall...both of which remind me of Necrozma-Dusk-Mane, which completely blew up the USM Ubers metagame. I'm not the best at Ubers, but even I know that Necrozma DM completely changed the metagame even despite being hard countered by Primal Groudon, giving Pokémon like Xerneas a much more reliable counter on top of having extremely potent sets for breaking apart walls once its counters like Ho-Oh and Primal Groudon were weakened. Zacian and Zamazenta both would have to compete with this on Showdown formats, Zacian for the offensive sets and Zamazenta for the defensive sets. The first thing I can say is that Necrozma-DM does not like running purely defensive sets that often since many teams would get all of the defensive utility they need out of one of its wallbreaking sets anyways. On top of this, if Zamazenta is part Fighting, then that would be pretty bad for it, since Fighting offers very few useful resistances that would let it be worth using over Necrozma. However, Zacian might be a little bit better off. Assuming it's Steel/Fighting, that STAB combo alone seems great for offensive sets, only really resisted by Ho-Oh off the top of my head...but I know not being able to counter Xerneas is huge, and not resisting Psychic anymore might really suck but I dunno. The fact that it has a better offensive typing might be a nice perk though, I mean it's enough for Mega Lucario to see use in Ubers despite there being some ridiculous mega options. It might depend on its Speed tier and movepool, honestly. I don't know though, again I'm not the best at Ubers. That's about it really. Their designs may be bad to me compared to other new Pokémon and mascot legends, but both of those have very few duds to me. The only other Pokémon I dislike that are mascot legends are the Necrozmas, since they don't have that same unnatural look that the Kyurems do despite being complete freaks of nature, and the only other new Pokémon I dislike is Wooloo, who looks really generic to me even if it's cute. I know I have an unpopular opinion on both Wooloo and these two, though.
