A long time ago, longer than anyone can count, an unknown champion was rewarded by the Aeon with a planet. The nameless ruler, under the grace of superior beings, had absolute power over his reality. However, the Aeon did not respond well to the deeds that followed. The oracles went mad, the future looked dark and turbulent. It is not known what the planet witnessed under the hands of that hazy champion. As a last interference, they sent a vengeful one - tasked with restoring or eliminating the threat altogether.

They say the combat lasted too long, until one day neither of them were worthy of the gift and of their own life. Faced with the destroyed planet, the Aeon learned from their mistakes - they were foolish and interfered too much. So, they turned them into dragons and sentenced them to the penalty of experiencing the pain that the deceased planet went through under their governance and battles. The corpse became a great ball of fire, called the sun. They, meanwhile, slept for years, wrapped around each other. They would have the chance to learn from the living beings that would flourish on their backs – perhaps, thus, finally managing to achieve the deserved and just peace of mind.

This is Dracaeon, Adventurers.
The Purgatory of the Combatant Dragons.