From May 4 to May 27, anyone can go to any GameStop location to get a code for Yveltal and Xerneas. However, unless you have both versions of the Gen 7 Pokémon games you will only be able to choose one of these Legendary Pokémon to download.

Xerneas can only be downloaded to Pokémon Ultra Moon or Moon versions. If you decide to download it to Pokémon Moon, it’ll come at level 60 with the moves Geomancy, Horn Leech, Night Slash and Moon Blast. and if you download it to Ultra Moon, it will be level 100 and holding the Gold Bottle Cap. It will come with the moves Geomancy, Focus Blast , Grass Knot and Moon Blast.

Yveltal can only be downloaded to Pokémon Ultra Sun or Sun versions. Downloading it to Sun will have the Dark and Flying-type and will arrive at level 60 with the moves Oblivion Wing, Dark Pulse, Phantom Force and Psychic. and downloading it to Ultra Sun will have it at level 100, holding a Gold Bottle Cap and come with the moves Oblivion Wing, Dark Pulse, Heat Wave and Tailwind.

to enter the code into your game follow these steps:

• start up either your Pokémon Sun/Moon or Ultra Sun/Ultra Moon game and select “Mystery Gift” on the main menu.
• Select “Receive Gift”
• Select “Get with Code/Password” and “connect to the internet”
• Enter the code on the GameStop card
• Then go to the nearest Pokemon Center and talk to the guy standing next to the counter, he will give you your pokemon and it will appear in your party.

There are also other Distributions for different legendary Pokemon trough out the year:

June – Shiny Zygarde

July – Tornadus & Thundurus

August – Kyogre & Groudon

September – Latios & Latias

October – Reshiram & Zekrom

November – Ho-Oh & Lugia