I'm thinking of a character who leads/is a new recruit in a group of dragon riders. Who act as mercenaries. Since Gen 1 and Gen 2 didn't have many dragon types outside Dratini's line, and maybe one or two stand outs. So maybe since they're a mercenary group they'd have dragons from different regions. Like Haxorus. Or the Deino line. Just an idea. 

Though have a new recruit be a royal dragon knight as also an idea.