Prologue: A world without arceus.
Arceus, the creator of the Pokèmon world. Father of time, space, and the very first Pokemon that was created as a base for all things, Mew. But Arceus wasn't the only one, He had a brother called Anitina. While Arceus created life, Anitina created death. He took things when it was their time, and often had Dialga help him with these things. Though Anitina did have a fascination with nature, he loved how it bloomed and that simple things had complex meanings. Arceus even created shaymin just for his brother, and Anitina just loved the little creature like it was a pet.
Though as time went on, Anitina noticed that humans had begun to feel superior. They ruined his favorite meadows for themselves, they captured pokèmon and force them to earn their trust, instead of gaining the poor creatures trust overtime by helping it. He was furious at the humans and wanted to punish them, Arceus calmed his brother to let the humans grow because they had been fascinating to him. Anitina silently sat in the shadows overtime and watched them, hating to take pokèmons' lives before they were supposed to end. Overtime he grew more distant, waiting for a reason to punish the humans, often fighting with his brother Arceus.
Though it was the day they destroyed shaymins home, and taking things for their own greed they had gone too far to Anitina. Furious at destroying the home of the shaymin, Anitina sent various creatures to go down and destroy the humans. He called their destruction a war sign, Arceus could not convince him to only punish the humans and not destroy them. It was too late and Arceus had gone to war, banishing Anitina to what is known as the distortion world today, and changing him to Giratina.
But that is for the human world, whatever happened to the seperate world were Humans don't exist, but only pokèmon? In that world Arceus never banished Anitina, and instead was murdered by his brother, failing to protect the humans and leaving them to defend themselves. And soon the statue of arceus in that world, was the last artifact to pray to arceus, the last hopes for humans for their savior to save them. But it never came, and soon humans went extinct. Anitina left the statue there as a reminder for what he done, but he could never recreate the home the Shaymins' once had and regretted his decisions.
Though he never forget the betrayal Dialga had done by fighting on Arceus side, along with other legendaries that he thought we're on his side. And sent nightmares to punish them and limit their powers. But some of the corrupted Pokèmon did more damage than what Anitina knew about, and thus Dialga bearing some of his Arceus's power. He created a human that soon transformed into a pokèmon due to traveling in space and time a lot from one of Anitina's henchmen. Though in the end, the human had survived and relived the punishment.
Angry at the thought of a simple being that was once human, and fixing a very bad mess he had overlooked; but he did like the fact of turning humans into pokemon and it gave him an idea, a VERY BAD IDEA! He knew there was other worlds were Arceus had probably succeeded in the battle, and he saw opportunity. He would capture one of the parallel arceus
and steal their power of creation, but he did not keep his plans secret, it got out quite fast. The human who had rescued her world from destruction, raced through to our world to warn the parallels of the oncoming doom.
The three Giratina, Palkia, and Dialga, started to form an army to protect Arceus without most of his knowledge. They gave out signature orbs to humans that granted them powers, it allowed them to turn into a pokemon matched the legendary with it's pelt color. They gained signature moves and abilities, and soon began to fight Anitina's nightmare's that he sent over to gain knowledge of how to summon him in that world, and where arceus's location was. They were called disciples of time, space, and distortion, They also fixed cracks in time and space, and closed off holes that weren't supposed to be their, and slowly anticipate when Anitina would bring his army and enter the world himself.