[GoseiWonder]

For Y players:
The (abridged) story of Xerneas that you hear in Anistar City
800 years ago, Xerneas made Kalos glow with life energy from it's kickass antlers. As this happened, a massive forest sprung up around the deer. It is also said that when Xerneas is close to death, it will share all of it's remaining life juice with the world.
And 300 years ago, during a horrible Kalos-wide war, it is said a Pokemon came to aid the wounded and many believe this to be Xerneas.
And now Xerneas is said to be in the form of dried up tree after the 800 years ago thing.

Now who wants to post Yveltal's story that you hear from the guy in Anistar City?