Prologue: Legends Become Legends
It has been five hundred years since it happened. Nature has entirely changed its course, having moved on from days of prosperity to a time of chaos and ruin. People in the current time can't even perceive the concepts of beauty or peace anymore.
And why? The legends are gone. They've went from their highly respected positions in culture to nothing more than children's tales. All because of one word: Seal.
Seal was an underground that group went totally unopposed and unbeknownst to people all across the regions as they completed their horrific mission: To rid the world of all legendary Pokemon. In their demented eyes, man alone should rule the Earth with Pokemon as merely no more than servants. Seal's nameless leader managed to rally up enough support in his men to ravage all of the Kanto region's legends, sealing them within small orbs of light. They still exist in their sealed forms, though no one knows where anymore. From there, Seal's horrific deeds spread across all other three regions. Pokemon after Pokemon fell to Seal's attack.
Finally, Seal reached Arceus himself, who descended down to stop the organization, seeing the destruction of all that he had created and nature being ruined. Smiting all of Seal's evildoers one by one, until all that finally remained was their leader. Even Arceus couldn't stand up to the brutal man's vicious onslaught. As the man drove a silver blade straight through the Pokemon's heart, he disappeared. And with his last breath, he had created hope for the world.
He had secretly created four magical keys, one for each region, knowing that one day four brave warriors would arise and awaken all of the legends from their eternal slumber. As for the leader of Seal, he disappeared as he and his organization had appeared, without notice, never to be seen again. Or so it is thought…