Invincible in the beginning

With all his strength, he has reached an unknowable and terrifying situation, nine heavens and ten earths, the number one master in the two worlds of gods and demons.
He is the most despairing terrifying demon king in history.
He is the best teacher, and the disciples he teaches are all dragons and phoenixes, rare and powerful in the world.
This is an invincible horror story of the great devil.