In a recent blog from Xbox Wire, Yasuyuki Oda shares a lot of interesting information about Fatal Fury: City of the Wolves latest DLC character – Chun-Li. Every time a crossover character makes it into a fighting game, it's somewhat of a special occasion. These collaborations tend to get special care that shows off the sort of care and reverence the developers have both for their colleagues, and the characters themselves.
Chun-Li's inclusion to City of the Wolves is no exception. One of the greatest challenges, which Oda highlights right away, is just the process of trying to take a character from one game, and seamlessly integrate them into another game. The drastic difference between the two titles makes it impossible to simply borrow or copy things, so it required thorough consideration from the developer team at SNK.
The Chun-Li that came over to Fatal Fury is ostensibly from Street Fighter 6, which might the most realistic Chun-Li has ever looked. This is something that didn't mesh well with CotW, which has a more anime-inspired aesthetic. This meant that artists at SNK had to carefully translate her features to a different style, while retaining the core aspects that must come through in her design, with "cool beauty" being one of the defining features.
This led to subtle touches like slightly slimming down her nose, giving her eyes a more fierce appearance, and even ensuring that her fingers still appear elegant despite her hands overall being bigger to match CotW proportions.
However, for one aspect of her design, the developers had to bend the rules to make sure they do the character justice. That is, of course, her legs. Chun-Li's legs have to be the most stand-out element of her design throughout the many iterations of Street Fighter, but adapting her to Fatal Fury, the developers found that her thighs come out way too slim, which apparently caused much debate. In the end, they has to add some more muscle to make sure it the design lives up to her legacy.
Lastly, they made sure to put just as much depth into her moveset and all sorts of unique animations. If you've been following Street Fighter and Chun-Li's crossover history, you should find a lot of subtle callbacks to Chun-Li's past appearances, this is something that SNK really wanted to come through within the game, so they consider it an "ultimate reward" if you manage to pick up on the little details they added.

