The cyan Ryu represents Karate Joe, a robed martial artist with a white color scheme.
The stage and music track represent "Karate Man", recurring martial arts-themed minigames of the Rhythm Heaven series.
The Crate items and battle conditions reference the gameplay of the "Karate Man" minigames, where Karate Joe has to use punches or kicks to hit objects that are send flying towards him.
Other trivia:
This spirit's Attack type and Fist Attack ↑ ability reference Karate Joe's usage of punch attacks.
