Prologue
It was time. Millenia had passed since Giratina had been banished. Arceus knew nothing; why should gods yield to the wills of humans? Humans were weak, pathetic creatures capable of nothing more than a few fancy tricks. Yet these tricks gave them the power to enslave any Pokemon they wished. Humans used Pokemon as tools, and treated them as slaves! Pokemon had so much more potential, so much more power. Some had the power to create worlds, and yet mere children were capturing them and forcing them to obey them! Children!
Darkness swirled as long, black tendrils flew through it, all attached to a single, centipede-like body. The outside world, the world Arceus had intended for everyone, was just beyond Giratina's reach. He could only look, for now. Humans had been using and abusing Pokemon for far too long; it was time to strike back!
A portal revealed a young boy facing the legendary Pokemon, Lunala. Lunala and her brother, Solgaleo, were two of Arceus' more loved creations. Arceus claimed to love all Pokemon equally, but he was lying. He had favorites. Solgaleo and Lunala could both create portals into some of the other dimensions Arceus had created. They always used this power to serve and help other Pokemon and humans. It was disgusting.
Of course, no Pokemon could compare to Arceus favorites. Other than Giratina, but he had been banished. Arceus had given his favorites dominion over time and space. They were gods, created to rule. These gods, and Giratina, were the only other completely unique Pokemon Arceus had created. All others had been given the ability to breed and reproduce, to grow and live life, and to one day die and pass on to the next world. Even the rejected Pokemon.
Giratina hadn't always been the renegade he was. Giratina was the first Pokemon Arceus created, and the most powerful. Arceus represented order, and Giratina was given dominion over chaos, meant to keep it in check. And for centuries Giratina did this. For centuries he had kept an eye on the chaos and made sure it didn't destroy what Arceus had worked so hard to create. And yet Dialga and Palkia were the ones who always received the praise and love. Arceus loved them, yet Giratina, who had the most important job, was often ignored and rejected.
Centuries of this abuse led Giratina to rebel. Giratina took the chaos he watched and used it to create. He created a world where the laws and order of Arceus ceased to function properly, and he created some Pokemon able to plant fear into the hearts of others. Pokemon that fed on chaos, rather than order. And they waged war. They fought a long battle against Arceus and his follows, but in the end they lost.
Giratina was banished to the world of chaos he had created, and Giratina's own favorite was stripped of his powers. He was partially imprisoned. The others, however, Arceus showed mercy. Arceus allowed them to live on the world he had created, along with the others, and gave them the same rights and privileges the others had. Even Giratina's favorite was shown some mercy; he was still allowed some freedom, albeit in a weakened form.
Most of the Pokemon Giratina had created accepted Arceus' mercy and abandoned Giratina, but his favorite never did. He was given immortality, and he continually plotted to in some way free his master and resume their attack on the world.
It had taken millenia, but Giratina finally had some way to escape. Giratina's revenge would soon take place, and the world would soon know the wrath of Giratina!