The Pokémon Global Link has announced the results of the Pikachu Cup and since Pikachu was the third most used Pokémon in the tournament, players that participated in the tournament can get a serial code to unlock Endeavor Pikachu. Details of this Event Pokémon have been added to our Event database.

Results Are In for the Pikachu Cup!

Because Pikachu finished third in the rankings, qualified players were sent a code to use to receive a special Pikachu in their Pokémon Omega Ruby or Pokémon Alpha Sapphire game. Codes were sent on Tuesday, September 1, 2015, following routine maintenance of the Pokémon Global Link. After the player logged in, a personal notification appeared that contained their code.

Source: http://3ds.pokemon-gl.com/information/22adf505-6ed3-4331-8ded-a68619abe927