After passing through Victory Road, the Championship Site lies atop the mountain.
Inside is a place to heal the player's Pokémon and buy items to prepare the player for the Tandor Championship.
The Championship consists of a 32-battle elimination tournament (putting it into the player's perspective, it is a typical 5-battle league challenge). Items other than held items cannot be used at all during the battles.
Participants include the eight Gym Leaders previously battled (with the exception of Hinata and Kaito), as well as other trainers that have their own specializations, such as Angelica, who specializes in the Fairy type.
The opponents faced by the player are random save for the championship match. The first two rounds of battle will always be with Goldkorn and Angelica (though not necessarily in that order), and the last two will be with 2 of the 7 gym leaders and Hokage. Just as competitors are randomized each runthrough, so are most of their Pokémons' abilities. After the first battle, the player will fight the characters that were previously seen in the waiting room.
After each battle, the player's Pokémon are fully healed and the player can make minor adjustments to their team to face the proceeding battles.
The final match of the championship is intended to be with the rival, Theo. However, the battle is interrupted by a nuclear Actan. The Actan is level 80 and will offer to join your party temporarily after defeating it. As of the 1.0.1 patch, the nuclear Actan can be caught, but will not be saved in your PC (See Actan's Trivia).
After some dialogue, the battle with Actan is followed by the final encounter with CURIE.