I have a new probable favorite ZEXAL character.
Anna Kozuki, while she's only appeared once, is my vote for best random character to appear so far.
Now, as I've noted, the younger ages of most of ZEXAL's characters is... a bit uncomfortable for me. They're much closer to actual children than most Yu-Gi-Oh! casts. But they don't really draw Anna here as a child (they even have her Gainaxing, for crying out loud!-also note that, if you don't know what that is, you should be cautious about clicking the link) and I guess that means that it's a bit less problematic for me.
Anyway, there are a lot of things about the character that are pretty great, so I'll list a few:
Her first appearance, mere seconds after the episode opens, involves her standing on a roof and sniping at the main characters.
With a cannon.
A cannon that can transform into a small aircraft.
Aside from the fact that she can and does wield a portable cannon with proficiency, even without that we have evidence of her being very strong-at one point, to punctuate a statement, she swings and misses at Yuma, and makes a small crater in a concrete wall.
And now we come to my favorite part of the character. Here we have a minor character (as opposed to an important villain or something, although the intro suggests that she may become a recurring character) who is a female duelist who does not use a single "girly" card.
Folks, that just hasn't been done before in Yu-Gi-Oh!'s various series.
Further, her few monsters are huge. They have a physical presence that's incredibly dominating, giant trains casually circling like sharks around Yuma and his tiny wimps, a presence greater than that of the vast majority of monsters since the Battle City era. And their statistics-one of them, in fact the first one we see, has 5000 ATK-are ridiculously hyperbolic.
So, in short, I think that this alone is perhaps the best thing about ZEXAL so far-equity in deck types. She's manlier than the guys, for crying out loud!
-Signing off.