Route 9 is just west of Opelucid City. It features Shopping Mall 9, and there is an entrance to Challenger's Cave, which you can access after defeating the Elite Four.
New Pokémon to Catch
Route 9 is the first place where you can catch Pawniard.
Trainers on Route 9
Biker Phillip has an L36 Krokorok and Scraggy.
Roughneck Reese has an L36 Krokorok and Garbodor.
Hooligans Jim & Cas each have an L37 Scraggy for a Double Battle.
Biker Zeke has an L37 Pawniard.
Roughneck Chance has an L37 Scraggy.
Shopping Mall 9
There are plenty of items to buy at Shopping Mall 9, including Timer Balls and Quick Balls, which couldn't be purchased in the locations that you have visited thus far. There is a room in the mall where you can change Rotom's form once you get one.
On the bottom floor, Waitress Flo will battle you with an L36 Minccino and Lilligant.
In the middle section, Rich Boy Manuel will battle you with an L36 Liepard.
On the top floor, you encounter Waiter Bert who has an L36 Minccino and Lampent, and Lady Isabel who has an L36 Stoutland.