At this point, the region of Sinnoh all that existed of Terra. The Spear Pillar resided in the center of Sinnoh, on top of Mt. Coronet. To mark a definitive location, The Original One resided in the back of the Spear Pillar. He called upon two Mews. One was called Ky, and the other Grou. The Original One told Ky that she was to expand the seas around Sinnoh, and that Grou was to expand Terra's defining thing around the seas: Earth. Ky was reborn as Kyogre, and Grou was later reborn as Groudon.
Kyogre's mission began first. She set out from what is now called Canalave City, which is currently one of Terra's most successful Docks. She sailed around the world and stopped in the Hoenn Circle, which contains the deepest seas in Terra.
Groudon's mission came second, but he learned nothing from Kyogre. He started from what is now the Sinnoh Victory road and went through what is now Seabreak path. When Groudon lost must of his energy, he released so much energy, that most of it became what is now Unova and Kalos. The energy that stayed close to him later became Shaymin's home.
When The Original One heard of Groudon's failure and death, he sent Qua to become Rayquaza to revive Groudon and bring him to Hoenn. On the way, dead parts of Groudon fell and became Johto and Kanto. Rayquaza revived Groudon in the center of the Johto-Kanto link, and Groudon's revival roar created the wall between Johto and Kanto. Rayquaza carried Groudon to Hoenn, and Groudon hated Kyogre when he saw her.
Rayquaza had to play peacekeeper, so the Original One created the Sky Pillar in the center of Hoenn so that Rayquaza may watch the two without needing to use the energy to fly.
Azelf, Uxie, and Mesprit were tired, so the Original One created Lake Valor, Lake Verity, and Lake Acuity in a triangle pattern around Mt. Coronet.
This is when life variety began to flow and the Mew population diminish. Each Mew species was reborn by the Male's name and his partner's agreement. For example, Mr. Seel and his wife became Seels. This is when reproduction was possible within all species but the Orignal One and his direct creations. The most important Mews were chosen by their personality values.
However, Mr. Seel would not change for millions of years after the Fossils.
The most intriguing thing about this age is the fact that some Mews did not evolve, and many important legends, such as Lugia or Victini, came into their own at an undefined time.
Of all the late legends, the most interesting origin story would belong to Xerneas, Yveltal, and Zygarde.
X, Y, and Z were all siblings, but their parents were only seen as spirits. It is thought that these three were an offspring of one of Evel's relatives.
X was a happy Mew, and everyone loved her, especially the Original One. She brought life to everything around her, and is thought to even have accidentally created Shaymin during a thanks prayer to the Original One.
Y was an angry Mew, and nobody loved him, except for the Forbidden One. He brought death to everything around him, and is thought to even have "accidentally" killed the fossil species during a stroll near Mount Coronet.
Z was an odd Mew, and nobody saw him, even the Grand Legends. He calmed down both X and Y when they fought, and is thought to even have been the stopper of one of Groudon and Kyogre's impossible, deadly fights.
It is believed that they evolved by outside of their own consent. Not even the Original One caused it. Instead, they spontaneously became Xerneas, Yveltal, and Zygarde out of their own definitive personalities.