Dragons were the most gifted warriors in Pan Gu world.
They inherited Saint Pan Gu's unbreakable physical body, and had indestructible scales, claws, and teeth. Their horns could even penetrate the sky, and their breaths could overturn the oceans and shake the natural stars.
Ever since the dragon-kind appeared in this world, dragons never dreaded anything. Back in the ancient time, dragons showed no respect to the heaven or the earth. They trampled upon the world, and did whatever they wanted. The heaven couldn't restrain them, neither could the saints. They were arrogant, violent, and domineering; facing them, all the other creatures in Pan Gu world would tremble.
All of this could happen because they were strong enough, especially the dragon ancestor and his nine sons. They were supernaturally strong, that not a single living being in this world could restrain them.