Yuffie duels against her father.
I always loved the whole adventure in Wutai, as full of funny situations, I found it somehow allowed to take a break in the main plot of the game.
Yuffie is one of my favorite characters, and the discovery of her hometown was a pleasure, as the ascent of the pagoda with the only fighter our favorite ninja.
The fight in question is in my memory quite a difficult time because there are four bosses to defeat in a row in one against one. But rewarded by the last limit of Yuffie.