Prologue
Long ago, before time and space existed, there was Chaos. Formless, dark, and unpredictable, nothing but the mighty Arceus existed to keep it in control. No one today knows of Chaos's true form, nor its capabilities. All that is known is its destructive force, and its name: Suecra. The being and Arceus were in constant battle, one seeking to perfect a world, the other seeking to prevent one from arising at all. It was at the dawn of creation, when Arceus birthed Dialga, the being of Time, Palkia, the being of Space, and Giratina, the being of dimension. It was through these three that the world was borne, and at this point Suecra knew that its power alone was unable to wreak the havoc it savagely desired.
Unable to prevent the creation of the new world, Suecra sought to bring about the destruction of it. However, between the Creation Trio and Arceus, there was no way for Suecra to overpower the beings. In a spurt of last resort energy, Suecra birthed its own trio: the Chaos Trio. The first to arise was Ignas, borne of the raging flame and the heated fury of the world's molten core. Following it arose Serpos, reigning over the coursing waves and raging gales of the sea. Finally, there came the youngest, head over all the chaotic lightning and howling fury of the storm. Between the three, Chaos began to overpower the Creation Trio, and then Arceus himself. The world was tearing apart at the seams.
Arceus began to fear the approaching turmoil, worrying that all he had strived to create would be ripped apart by Suecra and his titans. In the final hours before defeat, he gave birth to a third trio, seeking only to keep the forces of Chaos in check: The Legendary Knights. The first was Eosteel, Knight of the Dawn, who used an array of blinding rays and searing beams to distract and assault his enemies. The distraction held them off, preventing the destruction of the dimension, for the time being at any rate. After Eosteel's frontal assault, Hyperios, Knight of the Day, emerged. This knight was far more offensive than his tactical-based brother, and used his blazing light and massive power to weaken the enemy as much as possible. Finally, the third knight emerged. Seluna, Knight of the Twilight, took over the war and used her entrancing darkness and veil of silence to lull the already weakened titans into a deep slumber, allowing for their imprisonment within the space between dimensions known as the Void.
The world was saved, for the time being at least. However, there was no certainty that the prison would hold the titans forever, and as such, the Knights continued their patrol in an unending cycle, Eosteel in the morning, Hyperios in the heat of the day, and Seluna in the dim of the night, so that if their enemies were ever to arise again, they would be ready to defend their world.
Arceus realized that if no guardians were created to keep the forces of chaos in check, their reemergence would come much sooner than desired, and as such he created one additional trio, to keep watch over the posts of the Chaos Titans. Rayquaza monitored the realm of the sky, keeping the storms and weather in check and reporting to Arceus any signs of awakening. Groudon monitored the blaze of the core, the land remaining his domain. Finally, Kyogre was stationed in the sea, keeping the surge and tide under control.
For centuries things appeared to be under control, and only small outbursts of chaos came down on the world in the form of natural disasters. However, no prison lasts forever, and things are stirring in the plane of existence: Disasters, beyond the realm of imagination.