The Haunted

In the middle of the Unsteady Wars was the war of Light. Though the name sounds good, the true identity of the war is much darker.
Some wars are fought with might. Others, through political maneuvering. The War of Light, however, was fought with minds and strength of will, between four major thought-based Kinds:
The Waspera, who appear in the Temporal Realm as specks of light, and only appear under cover on a moonless night. They are most often sceaming and cowardly.
The Akkalion, who appear as whispery blue tigers during thunderstorms. They tend to be wise and fleet.
The Endrae, who appear as glittering dragons during tornados. They are usually strong and rash.
And, finally, the Fellio, who appear as fish that swim through the air as if it were water, while the moon is full. They’re unparalleled tacticians.
These four races raged silently, ravaging the Spirit Dimension but not touching the Temporal Realm.
As time wore on, the Waspera and Akkalion forged a treaty, as did the Endrae and Fellio. Both sides plotted against and destroyed each other, until, one day, a super-weapon was created.
The Embrio.
The Embrio was created by the Endrae and Fellio, who had found the tide of war turning against them because of a new Akkalion general named Alos-mere-io.
The Embro were originally stolen from a Fellio freelancer man scientist. It’s use was simple: once bonded to a specific beast, it granted them the ability to raze the souls of their enemies- at the cost of their own minds.
Wary, the Endrae-Fellio alliance first employed mercenaries and disgruntled citizens from the opposite side. But, once they saw how effective the Embrio was in combat, they branched out, pulling the most promising soldiers from their own side.
The Akkalion-Waspera side tried to upgrade defenses, but the Embrio were too strong. It wasn’t long before they were all destroyed, all but a few weary survivors wiped out.
Once it was clear that the war was over, the generals of the Fellio-Endrae called retreat, intending to pull the Embrio from the minds of their users, then either lock them away or start the hopeless road to acclimation.
But the Embrio were too far gone. Ignoring the orders of their superiors, they fled to the far reaches of the Spirit Dimension, stuck in the circuses of their minds.
As time went on, they dwindled in number, though each lived hundreds upon hundreds of years. They began to create songs to keep their spirits up, and that song spread until it could be heard by Empathic beasts in the Temporal Realm.
The verses changed depending on the user, but the chorus remained constant:
Then we will rise on the wings of freedom like some unknowable bird.
And then we will keen the song of laughter and flee to another new world…
The words were simple, but the tone of the song conveyed such a longing that all who heard it wanted to help these lost souls.
And so a new name formed for them: The Haunted.
Eventually they were all freed, but their legacies never died.