One random thing I really like in crossover materials is when a quirk or unintentional element of the original game is brought over in an interesting way that kind of makes sense whilst having its own take on the concept.
A good example of this is Kyosuke's sprites in
Capcom vs. SNK 2: Mark of the Millenium 2001. If you notice, not one of them actually has him ever clench his fist - which at first glance might seem like a weird point, until you realise why that is. In
Rival Schools: United By Fate, the character models weren't capable of animating or replacing hands - resulting in a lot of characters, by default, having clenched fist poses as you might expect. Kyosuke, on the other hand, has an open-palmed pose - resulting in all of his attacks in that game being performed with said pose. Like, I don't think it's an element anyone would have really picked up on if it
weren't included, but the fact that it
was is such a cool element.
Side note. Check out this
CVS2 lineup of him, Batsu and Hinata (given the other two appeared in his Level 3 super.) They look so goddamn GOOD here holy guacamole