black and white
in the battle subway
She will. At Route 2 , Route 4 Gate , Driftveil City , Route 8 & Juniper Pokemon Lab
Bianca
Fly to Icirrus City then battle Bianca on Route 8. After you win, she will give you some full restores and you will then go to Opelucid City.
If you mean play AS her, You can't. If you mean AGAINST her, you battle her several times throughout the game
in your own room,after that you have to battle both bianca and cheren
After you finish the game (completely) go to Professor Juniper's lab and Bianca will be there. Talk to her and your ready!
black and white
I believe she goes to Nuvema Town, that's where you can battle her
Find her in Prof. Jupiters lab and she'll battle you. Or go to serebii.com for more.
after you beat the 5 gym you have to go to route 6 and battle bianca after you beat her she will give you fly
If you found all 8 sages than she will be in professor Junipers lab and you can battle her everyday (her pokemon are crap though)
The battle is many beings battling against the black thing.
For regular trainers use the VS Seeker. You cannot re-battle the gym leaders though. You can battle Cheren in Victory Road and Bianca in Juniper's Lab.
in the battle subway
She will. At Route 2 , Route 4 Gate , Driftveil City , Route 8 & Juniper Pokemon Lab