A Wonderbolt cadet in training, he was inspired by hearing about the extreme risks that Rainbow Dash had gotten up to, and joined the Wonderbolts becuase of her, hoping that one day he can be as cool and respected as her.
Rush was a good flyer, but a risk one too, as he would always like to try out a lot of extreme stunts and tricks when flying, which makes his teammates worry about him that he is going o hurt himself one day. He himself also worries a little bit about this himself deep down, but he keeps doing them to try and prove how cool he is to try and impress others.
Despite this, Rushing Clouds is actually a very nice pony once you get to know him, and is more then willing to try and help stick up for others. Rush also likes to train a lot when he feels stressed out, as he feels the exercise helps make him feel calmed and relaxed.