The Book of Pokélantis (Also "The Book of Ancients") is an ancient, sacred item first seen in Pokémon XD^3: The Waves of Truth.
The Book of Pokélantis was authored by inhabitants of the ancient Pokélantis civilization before and during its collapse. It was then torn into pages and its pieces scattered around the Aquane Region.
Its pages contain a mysterious prophecy that predicts a horrible tragedy will befall the world. It is also imbued with powerful magic that may be related to the prophecy, which is why it was destroyed after being written.
Part One: found in the Cocoa Jungle Relic
Part Two: owned by Lyesainer, leader of Battle Mountain
Behold, these are the words of the ancients.
On this land a great and mighty king has reigned. But, he has made us suffer by seeking to contain the power of Ho-oh.
One man and one Pokémon have stood alone against the king’s strength.
Using his aura, the brave knight rescued the world from being plunged into darkness at the evil king’s hand.
Now, our time is ending.
But to protect the auras of the world, the brave knight with his last breaths created three Pokémon. A Pokémon each for the aura of wind, the aura of fire, and the aura of iron.
Thusly we name them the Aura Crystals.
We have scattered them to the winds and protected them with a secret mechanism.
Only the true descendants of the great knight will be able to awaken them and use their power to stop an even greater evil.....
This passage of the Book of Pokélantis describes the reasons behind the fall of Pokélantis as well as the deeds of Sir Aaron, a knight who sacrificed himself to save the world from being destroyed along with the ancient civilization.
The Emperor of Pokélantis attempted to capture the legendary Ho-oh, but his failure resulted in the destruction of his empire by the angry, wrathful Pokémon. With his last breaths the emperor sent two large armies to Ho-oh's home, the Tree of Beginning in another kingdom called Camaron, but on their way the two armies turned on each other and began fighting. Their battle combined with Ho-oh's rage threatened to destroy the Tree of Beginning and the entire world, but Sir Aaron's deed stopped the battle and pacified Ho-oh.
To end the battle, Aaron ventured to the heart of the Tree of Beginning, where he met the legendary Pokémon Mew. He used his ability to control Aura energy to transfer his own life Aura to Mew, which in turn transferred it to the Tree, creating a calming burst of light that ended the pending apcolypse. Without his life Aura however, Aaron died shortly after. As a result of his sacrifice, however, three Pokémon representing the Auras of the earth came into being. They are Metistyl, Flamistyl and Windistyl, known collectively as the "Aura Crystals."
The final line describes how the Aura Crystals must be used by Aaron's descendants to avert a tragedy beyond the scope of the one nearly triggered by the Pokélantis Emperor's greed.
The three Pokémon aligned form the bond between air, fire and steel that holds our world together.
Using the auras given to them in the last moments of the brave knight’s life, the three Pokémon bonded.
In the last moments of his reign the evil king has tried to seize the power of the three Pokémon. To protect them we sealed them away. Only the true descendants of the brave knight will awaken and use their power...
Two other Pokémon there were, at the beginning. One embodied time, the other embodied space. The evil king sought their power as well, so we also sealed them away.
They will not be sealed forever... when a new evil awakens the Pokémon of time and space, the descendants of the brave knight will forge an alliance of five heroes to use the power of the Pokémon and avert the destruction....