Rider

About

When Rider first appeared in the manga, he seemed to be egotistical. He did not care for his teammates, having only gathered them together to enter the tournament. However, after fighting and losing against Goggle's blue team, Rider began to care for his fellow teammates. While his serious attitude remains, he now enjoys himself while battling.
Occasionally, he'll help the Blue team by training them before they go up against a difficult opponent.

(Source: Coroika Wiki)