pearl: good friend, wants to be strong like his dad, gets beaten a lot too
His name is Diamond or Barry. Pearl is the girl's name. And "This new guy" (Which I assume you mean N) Wants to make everybody give up their pokemon. That's not exactly cocky.
His name is Pearl in the Manga, Diamond being the male player character and Platina the female one. Other than that, theres no other official info that actually determines who gets what game name. "In the Japanese versions, if the player doesn't give a name for the rival, he will be automatically named パール
Pearl in Diamond. In Pearl, the name ダイヤ
Dia is automatically given. In Platinum, either Dia or Pearl will be randomly selected."
while im at it, i see that i actually called green blue, his name should be green, as the first pair of games was actually green and red, blue coming along some time later
and you assume wrong, by this new guy, i mean the new rival in b/w2 with the round spiky hair.
i dont really consider green haired sissy a rival