sorry bout last answer you have to beat elite 4
you don't make sense atleast tell me which game like Pokemon firred,sapphire,ruby,emerald,gold,chaosblack,platinum,diamond,peaarl,
You have to beat the original champion in the game
In any Pokemon game, you must defeat the elite four and the champion.
the sinnoh league champion. defeat her and become the champion.
Gary until you beat him and then you get put into the hall of fame and you become champion
you defeat all the elites(4 of them) and the previous champion
Go to the Pokemon league and become the champion
capture the legendary and train your Pokemon
I Guess maybe
technically, when you beat the Pokemon league, you become the champion. but you cannot really fight as a part of the Pokemon league
You become the champion by beating Cynthia and you have to battle everyone in the game to get the national dex
There is no key it opens when you become a Pokemon champion.
Beat everybody else.