A lonely Xerneas lived in a once great forest. The forest had shriveled and was close to death, as was the Xerneas. It had no will to save the forest, nor itself. It simply sat in a cave, and decided to rot.
Then came along four Pokémon, a family of Shaymin. Winter, Spring, Summer, and Autumn.
Winter, with her quiet understanding, sat with Xerneas in its rest, and the two simply spoke.
Spring saw the Xerneas' garden that had once been bountiful, and began to sow new seeds. She cared for the garden as if it were her own, and soon life began to sprout once more.
Summer convinced the Xerneas to step outside of the cave, and to enjoy the garden. To see what was possible with a little bit of care. To play with her and her sisters.
Autumn gathered the crops, and gathered Xerneas and her sisters for a feast. They all prepared the meal together, and ate it together. The Xerneas could not help but feel joyful, but also perplexed. Why were these Shaymin treating him as if it was family? Why show it such kindness?
The Shaymin simply laughed. They replied, "We do whatever we can to help who we are able to, as long as we are able."
The Xerneas was moved, and asked the Shaymin to stay with it, and help restore the rest of the forest. To create a new balance. A mighty task, but they would each be given a gift to help...
The forest would slowly be revived, each section of it taking on its own ecosystem and climate. The Shaymin could not live forever, but they made sure their gifts would be passed down to trusted descendants, who watch over the forest even now.
This did not bring comfort to the Xerneas. It went into a deep sleep after its friends all passed. And still it sleeps, at the center of the Forest..