Huckleberry
Poison Trainer
I was expecting the starters' secret to be revealed with them. I am thinking it may be in the next CoroCoro, however.
Do keep in mind that CoroCoro tends to be melodramatic as well. It's entirely possible the "secret" is their evolutions. I'm not trying to rule out the possibility of something like unique Z-moves, mind you, but don't be entirely surprised if nothing comes of CoroCoro's hyperbole.