Is the battle subway something i have to connect to internet/wifi to battle on?
No, but there is 1 train you need Wi-fi for.
The Wi-fi train, the colour is Light Blue.
Hope this helps!
No, the battle subway is the equivelant of the battle tower/frontier in any other pokemon games. you don't need wifi to do the battle subway
But A Room With Light Blue Colored Stripe
Is The Wi-Fi Train, You Will Need Wi-Fi As
The Name Suggests :)
Hope I Helped :)