In this image, there's a person standing in front of the dragonium z instead of just a substitute. Is he acutally a character from SM? If he is, what's his name? Please don't question my curiosity.
Well thats partially true. We know his name its Ryuki and he is a Dragon type specialist from another region and he's also a musician. He's not the dragon trial captain as there isn't one as far as the game goes. Not much else is known about him though as he is just one of the random trainers who can challenge you for your spot as champion when you defend your title.
Source: Experience and Serebii