Hey, Keldeo is this month's event pokemon! The event runs from Saturday 1st October to Monday 24th October 2016.
The Mythical Pokémon Keldeo first galloped into Pokémon Black and Pokémon White in Ordinary Form, and then changed into majestic Resolute Form after learning the Secret Sword move in Pokémon Black 2 and Pokémon White 2. Now you can get Keldeo via a Nintendo Network event, once again in Ordinary Form in Pokémon Omega Ruby and Pokémon Alpha Sapphire! Then, seek out the Move Tutor in Mauville City to teach Keldeo its signature Secret Sword move.
Download Keldeo via Nintendo Network beginning October 1, 2016, for your Pokémon Omega Ruby, Pokémon Alpha Sapphire, Pokémon X, or Pokémon Y game. This Pokémon will be available only until October 24, 2016, so don't miss this opportunity!
Details to download can be found here:http://www.pokemon20.com/en-gb/mythical.html#oct
And a nice little trailer here: https://www.youtube.com/watch?v=MpNUTuREltw