This Challenge Hall is a place that seems empty often throughout the game, so it's easy to miss when it is relevant. There are several times during your journey that it will open with a tournament called the Challenge Cup. Be aware that if you earn a medal while the Challenge Cup is going on, it will end.
The Challenge Cup is a tournament where you face 3 opponents in a row, and if you beat all 3 you earn yourself a promotional card. However, if you lose to even one of them, you'll lose the cup and not get anything. You can save between duels though, so this shouldn't be a problem. Your first two opponents will be randomly selected from the club members of each of the clubs. Your final opponent for the Challenge Cups based on having medals is always Ronald. He'll be using his Invincible Ronald Deck.
The Challenge Cup will be available at two points as you progress through the game:
- After you earn 3 medals.
The 3 medal Challenge Cup rewards you with Mewtwo P12.
- After you earn 5 medals.
The 5 medal Challenge Cup rewards you with Mew P14.
Once you've defeated the Grand Masters in the Pokémon Dome, the Challenge Cup will also randomly be available when you load your save file.
The Challenge Cup after defeating the Grand Masters rewards you with any of the following cards randomly:
- Arcanine P01 - this is also available in a trade at the Water Club.
- Pikachu P04 - this is also available in a trade at the Grass Club.
- Pikachu P05 - this is also available in a trade at the Fighting Club.
- Flying Pikachu P06 - this is also available in a trade at Ishihara's House.
- Surfing Pikachu P07 - this is also available in a trade at Ishihara's House.
- Surfing Pikachu P08 - this is also available in a trade at Ishihara's House.
- Electabuzz P09 - this is also available in a trade at the Lightning Club.
- Slowpoke P11 - this is also available in a trade at the Fire Club, however you can miss that trade permanently if you say "No".
- Mewtwo P12
- Mewtwo P13 - this is also available for beating Murray and talking to Pappy in the Psychic Club.
- Mew P14
- Jigglypuff P15 - this is also available for beating Ronald after getting your second medal.
- Super Energy Retrieval P18 - this is also available for beating Ronald after getting your fifth medal.