A long time ago; in the world of Pokémon, before the time of trainers; there was a legendary Pokémon that only knew compassion towards humans. Yet, humans feared it; not because it was ever hostile, but because of it's unstoppable strength.
The Pokémon had towed the continents of the world, separating groups of waring humans to where they now reside. The humans whom shared their home with the Pokémon feared that it would one day turn it's massive strength on them. They, however, knew better than to provoke it. The Pokémon lived it's days out in relative peace, sitting in the snow blanketed forest, observing it's inhabitants.
One day, fear grew among the humans until they lost sight of all reason. A young man provoked the fear of the people to its breaking point; claiming that he had witnessed the great Pokémon destroying trees trees in the forest. The people, whom had never witnessed the Pokémon committing any act of aggression, readily believed the young mans story.
They attacked the Pokémon, driving it into a deep cavern dug out by a falling star. The Pokémon had not resisted; it ran away from the humans, going were they pointed it. Even through the onslaught of fire and stone, it endured. Once the humans cornered it, they sealed it inside, deep below the surface.
But, before they sealed the Pokémon away, it created three beings in its image from the remains of the fallen star. One; from the frozen shell of the fallen star, a being of ice so cold it would never melt even under the hottest of flames; the second; from the crust of the fallen star, and stones surrounding, a being of stone and earth; the third and last; a being from the very core of the fallen star, of metal so strong, nothing can scratch it.
The Original One began to enter a deep slumber, leaving its creations with this edict, "One day, the humans will forget about me; one day, the humans will no longer fear me; and when that day comes; one of them will come forth to find me and set me free."
And so the three beings departed for parts unknown; lying in wait for their masters champion.
How long they wait; how far they travel; continues to endure to this day.