Yoichi can be considered as a slightly weaker version of Le'boin, as he has a higher damage output, twice the speed, and shorter attack frequency, but 10 less range allowing Dragon Cat to outrange him and slightly less HP (more noticeable by his extra knockback). Yoichi also has a longer attack animation in both foreswing and backswing, making him easier to stall.
Turn the animation on and off using the switch in the upper left. Clicking the viewer background enables scrolling and zooming with the mouse if on desktop. Note that browser zoom may cause issues with scrolling and zooming. A list of available backgrounds can be found here. For more info on usage, see here.