Disclaimer: I don't own Pokemon.
Once upon a time, people say in hushed tones, a heroine arose. A simple girl from the country, she had an almost magical connection with pokemon. So when she left on her pokemon journey she took Unova by storm. But her journey would not be easy, because along the way she found that she was the heroine of legend, come to fight for the truth and save Unova from the evil Team Plasma's goal of separating humans and their pokemon. So she worked and worked to be strong enough to save the world, to defeat Team Plasma's king, N. And she did.
But there was one problem.
She fell in love with him.
And when she won, his father disowned him and revealed that the king had been no more than a pawn. The heroine beat this man as well, her Reshiram by her side.
But N's world was shattered, so though the heroine pleaded, he left her to find himself, telling her to follow her dreams.
But the young king forgot to take one thing into account.
According to the legend of the dragons, the beasts were forever linked, two halves of one whole. When the heroine and the king were accepted by the legendaries, they became forever linked as well, unable to survive without one another.
So the heroine stopped living, watching and waiting in the remains of his castle for him to return.
And when the League dismantled the castle, as it was surrounding the Elite Four, she waited at Dragonspiral Tower. For years and years she stood or sat, looking off into the distance, peering at the horizon, waiting for a spot of black or the crackle of blue electricity.
Nothing her friends or family said got through to her, either; she didn't even seem to hear them. The heroine's mother hired a detective, Looker, to find N, to get her daughter back to normal.
About three months later, he found a small, strange tan cube washed up on the beach at Route 13.
She still didn't hear.
And she continued to watch the horizon from the tower until she died peacefully, looking for black.
Once upon a time, people say, a heroine rose and fell in the blink of an eye, and was buried with a cube.