For both of the competants this was their dream fight: a fight where their opponent is somebody who embodies in their eyes the ideal of a knight. A fight where they can at the same time prove their nobility as knights, and receive the peak of their happiness as knights. A fight where they are both on the same wavelength, and thus a fight that is the most fair possible. That's one half of the basis for why the animation was how it was. The other half was their focus. Because both use techniques that rely on short bursts and utmost focus, they both threw every drop of focus and energy they had in themselves in just one swing. All of this was coupled with animation that differed the two characters mostly by one color: red for Ikki, yellow for Touka. Every other color they have is gradually left behind (literally shown as the color withdrawing) in the process of their build-ups for their swings. Because they lose sight of everything else in the world, including even colors. Because they focus only on that one swing they must do in order to fulfill their ambitions and happiness. And all of this is the same for both of them. All of the context and feelings thrown in the fight, represented in an easily understood and gorgeous way by the animation. This is what animation is for.