New Pokemon Movie To Feature Xerneas, Yveltal And Mega Evolution - Siliconera

The first movie involving the legendaries of Pokémon X and Pokémon Y is scheduled for release in Japan next July.

Pokémon X and Y, Nintendo 3DS Wiki

Pokemon Ultra Sun/Moon - Xerneas & Yveltal Trailer

News - June, 2013

Pokémon X and Y, Nintendo 3DS Wiki

List of Pokémon, Ultimate Pop Culture Wiki

Yveltal vs. Xerneas & Mega Diancie ~Pokemon~AMV~

Pokémon X and Y, Nintendo 3DS Wiki

Pokémon - It's the Pokemon thread, Page 2

Mewtwo Has Two Mega Evolutions In Pokémon X And Pokémon Y

Pokémon - It's the Pokemon thread, Page 2

Pokémon X and Y - Wikipedia