Prologue
War. War never changes. Long ago, man and Pokémon lived together in harmony, as partners and friends. Some used Pokemon to help with day-to-day chores, others kept them as pets. Others, still, trained them and used them for battle. We called these people Pokémon Trainers.
For a time there was peace. Trainers traveled across the land searching far and wide for new species of Pokemon. Somewhere along the way, though, mankind lost the thread of partnership.
Where man once saw Pokémon as friends, soon they turned to using them as weapons in wars against each other. Eventually, someone created a Pokémon with enough destructive power to end all wars. Using the phenomenon of Mega Evolution, they pushed the Pokémon Electrode to evolve into a never-before-seen creature: Megaton.
When Megaton performed the "Self Destruct" move, the explosion was enough to level entire cities. It wasn't long before the leaders of the many regions decided to end it all.
While the strife and tension rose, one company thought to do something to ensure the future of man and Pokémon alike. Silph Co. created the first underground fallout shelter known as PokéVaults. Here man and mon could live together until the radiation of the explosive Megatons dissipated to a reasonable level.
When the first bombs began to blow, people were ushered into the vaults, along with their Pokémon, and to this day they've remained closed. Some say that one of those vaults will open one day, and some brave young trainer could emerge to set things right.
Anything is possible. But the important thing to note is that no matter how noble a cause may be… war never changes.