Walkthrough
With all eight Gym Badges now obtained, you will now be able to proceed past the Check In Gate on Route 23 just past Route 22. However, as you enter Route 22, your Rival will appear. He has also defeated all eight Pokemon Gyms, and he, too, is looking to challenge the Pokemon League. Because of this, he will challenge you to another battle. Since your last encounter with him, he has trained his Pokemon Team and has even added a sixth member to it. After defeating him, he will proceed towards Route 23 before you do.
Rival (Bulbasaur Chosen): Level 47 Pidgeot, Level 45 Rhyhorn, Level 45 Exeggcute, Level 45 Gyarados, Level 47 Alakazam, Level 53 Charizard
Rival (Charmander Chosen): Level 47 Pidgeot, Level 45 Rhyhorn, Level 45 Growlithe, Level 45 Exeggcute, Level 47 Alakazam, Level 53 Blastoise
Rival (Squirtle Chosen): Level 47 Pidgeot, Level 45 Rhyhorn, Level 45 Gyarados, Level 45 Growlithe, Level 47 Alakazam, Level 53 Venusaur