Unanswered Playable Trainers. Unlock others?

[CrownedWingz]

Is there a way to unlock Blue from FireRed/LeafGreen as a playable trainer in this game? I believe I've seen a few people with Blue as their sprite trainer in the open world of this game. If he is obtainable, how to you get him? Only Brendan and May seem to be the only gen 3 protagonists that are playable.

[Kogamaster1234]

All the characters are playable in the profile page, you can select your avatar there and you don’t have to unlock any, you can even play as Giovanni, so basically all characters are playable in profile page and you don’t have to unlock any of them