Teach your Bagon Flamethrower and/or Brick Break, and have him battle the two Magneton trainers on Cycling Road and Aroma Lady Rose and her grass types. Another option, not necessarily for Bagon, but for any Pokemon, is to go DEEP into the Meteor Falls. The Solrocks give 700-800 EXP and the Golbats give 800-900 EXP. It's better than Victory Road because Victory Road is home to a bunch of Zubats, Arons, Makuhitas, and Mawiles who
give almost no EXP. In Meteor Falls, you are bound to get either an EXP-laden Golbat or a Solrock. Training Bagons are a PAIN though so I advise the Breeding Center until he's at least Level 38-40...
