Before Time there was only Order and Chaos, two forces of nature that with the passing of eternity took shape. The Order took the form of Arceus and from the Chaos, Giratina arose. Arceus then created the beings of Time and Space, Dialga and Palkia, and the three together, began to create the universe. An order-based universe, where Giratina had no authority.

Giratina seeing this, felt angry and betrayed, with fury in his heart, he then decided to create a new dimension, a dimension that consisted only of Chaos. A dimension where Space and Time were one. Arceus, knowing that Giratina had created a dimension for himself, decided to imprison him there for all eternity, for Arceus feared a being as powerful as himself.

Giratina realized that something was wrong and decided to confront Arceus, but that was not necessary. Upon leaving his dimension, he encountered the Three Creation Beings waiting for him. They told him to go back to his dimension and not leave. Giratina refused and thus began a battle that lasted for centuries and a war still without end.

As time passed, Giratina increasingly realized that his struggle was in vain, so he decided to use his last forces to collide his dimension with that of Arceus, creating a fissure in Space-Time that he could cross at will. Giratina, defeated, returned to its dimension. Arceus then created a pokémon to guard the fissure and slept, leaving Dialga and Palkia to create the rest of the universe.

While Arceus slept, Giratina kept awake, plotting his revenge, even attacking Dialga and Palkia during Arceus's sleep, but one night he slept ... and in his dreams, a pokémon approached him, Cresselia, a pokémon created to hold the Kingdom Of Dreams, a perfect place where humans and pokémons traveled to while sleeping.

Giratina dreamed but its dream was so perverse that Cresselia was corrupted by it. Darkness began to engulf her and when she was all consumed by it, Darkrai was born and at birth, the Kingdom Of Dreams was ripped in half, a half being normal, and the another being deformed, empty.

Giratina then started his revenge plan, he used the power of Darkrai's nightmares to create chaotic versions of the Pokémons that Arceus loved so much. For the Sun, he created the Storms, for the Earth he created the Seas for the Truth he created the Ideals and for Abundance he created Forces of Nature capable of ending it.

And now, he eagerly awaits the time of his uprising, the time to get revenge on Arceus and usurp his authority as the One And Only, and when he does, he will create another universe, a perfect one, one that is made of chaos, one that resembles his Reverse World.