Question

Because I've prety much finished the game.

Answer 1

I wish. But no it's not possible.:)

Answer 2

Nope, although there is the battle frontier. Comment if you haven't gotten to it yet.

Comments

Ah... I'm late...

Answer 3

You can't go to another region, but you can get out-of-sinnoh pokemon through the pal park and battle frontier

Answer 4

You can't go in another region.
but you can get all the starters