After becoming the Champion, you'll gain access to the Battle Frontier, located on the Fight Area island (accessible via the ferry from Canalave City). The Battle Frontier is a challenging post-game area designed to test your battling skills. It consists of five different facilities, each with its own rules and challenges:
- Battle Tower: Standard battles against trainers.
- Battle Factory: Rent Pokémon and battle with them.
- Battle Arcade: Spin a roulette wheel to determine battle conditions.
- Battle Castle: Manage Castle Points to buy items and information.
- Battle Hall: Focus on a single Pokémon type.
Conquering these facilities and defeating the Frontier Brains will earn you commemorative prints and Battle Points (BP), which can be exchanged for valuable items and TMs. It's the ultimate test for any aspiring Pokémon Master.