Yang Dao and Dao Yin were immersed in their first tryst of pleasure, this moment in time was the testament that they were one. The previous Dao Masters did not form a union with each other because they never went through the phase of growing up. To them, the balance of Yin and Yang existed because they were together and they were the embodiment of Dao.
They were correct in a way, however, as the world changed so did the essence of Dao. The two masters, were the embodiment of the Dao that was not complete, something that had no experience of what was 'Change'. So, when they faced attacks from the void, they could not adapt and fell.
However, the two children had seen not one but two lives. They have seen changes, from being an orphan to having loving families, poor to rich, weak to strong. Yes, they were overpowered, but they were weak in the beginning.
