When his enemy drove his dragon into the abyss, the whole continent thought he was useless. Until the world-destroying dragon flames burned through the nine heavens, the young man spurned by the dragon clan sat at the bottom of the abyss: "Who said that without a dragon, you can't ride a dragon?"
When the abandoned son of the past reappeared on the continent dragging an abyssal bone dragon grown from the corpses of gods, thousands of dragons were silent - don't mess with him, his dragon has a bigger temper than he does.